Use of acth in assessment and prophylactic treatment of hypokalemia associated with glucocorticoid receptor modulator treatment of cushing&#39;s syndrome patients

ABSTRACT

This invention provides new methods for a) identifying Cushing&#39;s Syndrome patients at high risk of developing hypokalemia during glucocorticoid receptor modulator (GRM) treatment, and b) for prophylactically treating such patients to prevent, or reduce the severity of, hypokalemia. Patients at such high risk may be identified prior to their developing hypokalemia. Such a patient may be an adult patient with endogenous Cushing&#39;s Syndrome having type 2 diabetes mellitus or glucose intolerance to control hyperglycemia secondary to hypercortisolism. Patients may be identified by an above-threshold level of ACTH or cortisol in a patient sample taken post-GRM administration or pre-GRM administration, respectively. Upon identifying such a patient prior to the development of low potassium, the present methods provide for prophylactically treating the patient by administration of one or more hypokalemia treatments concurrently with an increased dose of GRM or with an initial dose of GRM to prevent hypokalemia.

RELATED APPLICATIONS

This application is a U.S. Continuation of application Ser. No.16/266,477, filed Feb. 4, 2019, which is a U.S. Continuation ofapplication Ser. No. 16/109,561, filed Aug. 22, 2018, (now U.S. Pat. No.10,231,983, issued Mar. 19, 2019) which claims priority to U.S.Provisional Patent Application No. 62/693,318, filed Jul. 2, 2018, thedisclosures of which are hereby incorporated by reference in theirentireties for all purposes.

BACKGROUND

Cushing's syndrome, characterized by hypercortisolemia, is a conditioninvolving a prolonged excess of circulating cortisol. Excess circulatingcortisol leads to excess cortisol binding at the glucocorticoidreceptor, which in turn causes a wide array of serious symptoms,including one or more of: hyperglycemia; hypertension; abdominal obesityand thin arms and legs; facial plethora; acne; hirsutism; proximalmuscle weakness; bone loss; easy bruising; and red purple stripes acrossthe body. Cushing's syndrome patients are at increased risk ofhypertension, cardiac arrhythmias, atherosclerosis, and othercardiovascular disorders. Cushing's syndrome can be classified asexogenous Cushing's syndrome (caused by excess use of glucocorticoidsdrugs, such as prednisone, dexamethasone, and hydrocortisone), andendogenous Cushing's syndrome (caused by deregulatory abnormalities inthe hypothalamus-pituitary-adrenal (HPA) axis). Endogenous Cushing'ssyndrome consists of Adrenocorticotropic hormone (ACTH)-independentCushing's syndrome, characterized by an overproduction of cortisol inthe absence of elevation of ACTH secretion; and ACTH-dependent Cushing'ssyndrome, characterized by excessive ACTH secretion.

ACTH-dependent Cushing's syndrome includes roughly 80% of patientshaving endogenous Cushing's syndrome and consists of two major forms:Cushing Disease and ectopic ACTH syndrome. The former is typicallycaused by a pituitary tumor and the latter is typically caused by atumor outside the pituitary. Tumors may produce and secrete proteins andhormones such as corticotropin releasing hormone (CRH), ACTH, and/orcortisol, for example. Such proteins or hormones may not be active, ormay only be partially active; see, e.g., Mathioudakis et al., Pituitary15(4):526-532 (2012)). Correct differential diagnosis between theCushing Disease and ectopic ACTH syndrome is important forendocrinologists to recommend transphenoidal surgery or appropriateimaging to identify source of the ectopic ACTH secretion. Thus, when apatient is identified as having a pituitary tumor (Cushing Disease),transsphenoidal surgery is indicated, and should be performed to remove(as much as is possible) the tumor. Patients identified as having anectopic tumor (ectopic ACTH syndrome) should have appropriate imaging,and, if the source of the ectopic ACTH secretion is located, surgeryshould be performed to remove (as much as is possible) the tumor.However, some patients may not be candidates for surgery, or may failsurgery (e.g., not all the tumor may be removed). Patients that are notcandidates for surgery, or who fail surgery, will likely benefit fromtreatments which block the effects of cortisol, such as treatment with aglucocorticoid receptor modulator (GRM).

Endogenous Cushing's syndrome patients may be treated by administrationof a GRM. A GRM modulates the activity of a glucocorticoid receptor(GR). The GRM may be, for example, mifepristone. A GRM that antagonizesactivation of the glucocorticoid receptor (GR) by GR ligands may also betermed a glucocorticoid receptor antagonist (GRA). Antagonistic activityof a GRM is typically effected by interfering with ligand binding to theGR. The main endogenous GR ligand is cortisol; artificial GR activatingligands include, e.g., dexamethasone, prednisone, and others. In thecase of the GRM mifepristone, the GR modulation includes reducing theactivity of the GR. Mifepristone administration, typically once-dailymifepristone administration, is used to treat Cushing's syndrome inpatients, including ACTH-dependent Cushing's syndrome patients. Due totheir elevated cortisol levels, Cushing's syndrome patients have anincreased risk of developing hypokalemia, which occurs when cortisollevels are so high they overwhelm the enzyme (11-β hydroxysteroiddehydrogenase) that metabolizes cortisol to cortisone and so protectsthe mineralocorticoid receptor (MR) from cortisol, resulting indecreased potassium levels in the patients. Because GRM treatment raisescortisol levels even higher (even as the GRM reduces binding at GR),Cushing's syndrome patients treated with a GRM are at a significantlyincreased risk of developing hypokalemia. As hypokalemia is one of themost common adverse events associated with GRM treatment, it isimportant that the risk of developing hypokalemia among Cushing syndromepatients receiving GRM treatment be assessed and, when necessary, beaddressed.

Hypokalemia (low potassium levels) is a serious condition, which canlead to cardiac arrhythmias and other cardiovascular disorders, and maybe life-threatening. Potassium level is typically measured in apatient's blood stream, especially in a serum sample or plasma sample,according to methods known in the art. Normal potassium levels aretypically between about 3.5 milliEquivalents per liter (mEq/L) to about5.3 mEq/L. Patients with hypokalemia have low potassium levels (e.g.,between about 2.5 mEq/L to below about 3.5 mEq/L); patients withpotassium levels below about 2.5 mEq/L have severe hypokalemia. Patientssuffering from hypokalemia may experience fatigue; edema; hypertension;muscle weakness, cramps, or muscle spasms; neurological problemsincluding paresthesia and paralysis; renal problems such as polyuria,polydipsia, and nocturia; gastrointestinal disorders including abdominalcramps, constipation, nausea, and vomiting; long Q-T syndrome; cardiacpalpitations and arrhythmias; and may be at risk of sudden cardiacarrest; and other symptoms and disorders. Hypokalemia, and inparticular, severe hypokalemia, may require hospitalization fortreatment and monitoring until normal potassium levels are regained.Hypokalemia may be treated by administration of a potassium supplementor a potassium sparing diuretic. Conversely, administering thesemedications to patients who are not hypokalemic and not at risk ofdeveloping hypokalemia has adverse implications: for instance,hyperkalemia can result and lead to significant dangers to the patients.This is an important reason why it would be very valuable to be able topredict the condition and ensure proper treatment of Cushing syndromepatients being treated or to be treated with GRM administration.However, means and methods for making such predictions are lacking inthe art.

It would be advantageous to patients and treating physicians to be ableto reliably predict which Cushing's syndrome patients are most likely tosuffer from hypokalemia while receiving mifepristone for the treatmentof Cushing's syndrome. However, reliable predictive markers have notbeen identified. For example, although cortisol may be measured in blood(e.g., serum or plasma), urine, and saliva, the levels measured in theseways differ and do not correlate with each other. Urinary free cortisol(UFC, a measure of cortisol in urine excreted over 24 hours) is used todiagnose Cushing's syndrome; however, UFC masks the daily cortisolvariations by requiring a full day's sample; in addition, UFC tends tohave significant variability as it may be affected by the volume offluid intake by the patient during the day and may be affected by thepresence or amount of impairment of kidney function (Rosmalen et al.,Psychoneuroendrocinology 47:10 (2014)). Alternatively, plasma cortisol(a measure of the cortisol levels at the time the blood sample is taken)is used for dexamethasone suppression testing (which tests patientresponse to rapid increases in glucocorticoid levels). In addition,cortisol level can also be measured in a serum sample according tomethods known in the art. As noted above, Cushing's syndrome ischaracterized by high levels of cortisol. Putignano et al. found nocorrelation between urinary free cortisol levels and either mean plasmacortisol or mean salivary cortisol levels; and that although salivarycortisol correlated with plasma cortisol levels in a population of 290women with a wide range of cortisol levels, that correlation was lostfor plasma cortisol concentrations greater than 500 nanomoles per liter(nmol/l) (Putignano et al., Eur. J. Endocrinol 145: 165-171 (2001)). Inaddition, Fleseriu et al. state that “[b]ecause mifepristone does notdecrease cortisol production, measurement of this hormone should not beperformed during treatment”, and Torpy et al. state that “[t]here was nocorrelation between ACTH level and hypokalemia” (Ann. N.Y. Acad. Sci970: 134-144 (2002).

The HPA axis is involved in maintaining proper potassium levels; thus,Cushing's syndrome, which is characterized by dysregulation of the HPAaxis, includes the risk of developing hypokalemia. Cushing's syndromepatients at risk of developing hypokalemia include endogenous Cushing'ssyndrome patients, such as, e.g., ACTH-dependent Cushing's syndromepatients. In a study of Cushing's syndrome patients (including bothACTH-dependent and ACTH-independent Cushing's syndrome) treated withmifepristone, 22 (of 43) patients had serum potassium levels less than3.5 mEq/L, of whom 3 had serum potassium levels less than 2.5 mEq/L(severe hypokalemia) (Fleseriu et al., 2012). Thus, significant numbersof Cushing's syndrome patients treated with mifepristone are at risk fordeveloping hypokalemia. As noted above, hypokalemia can lead toincreased risk of cardiac arrhythmias and other cardiac, muscular, andnervous system disorders. Cushing's patients may be at increased risk ofcardiac arrhythmias, high blood pressure, and atherosclerosis;hypokalemia could further increase these risks, and could increase therisk of other disorders caused by, or associated with, hypokalemia.

Accordingly, methods for the identification of Cushing's syndromepatients who may be at high risk of developing hypokalemia are desired.Similarly, methods for reducing the risk of, or preventing, thedevelopment of hypokalemia in Cushing's syndrome patients at high riskof developing hypokalemia are desired. Methods for reducing the risk of,or preventing, the development of hypokalemia in ACTH-dependentCushing's syndrome patients at high risk of developing hypokalemia aredesired.

SUMMARY

Cushing's syndrome patients are at risk of developing hypokalemia, aserious and potentially life-threatening disorder. For example,Cushing's syndrome patients being administered a glucocorticoid receptormodulator (GRM), such as Cushing's syndrome patients receivingglucocorticoid receptor antagonist (GRA) treatment, e.g., receivingmifepristone treatment, are at risk of developing hypokalemia. Applicantdiscloses herein that such Cushing's syndrome patients may beparticularly at risk of developing hypokalemia after initiating GRMtreatment, or after an increase in their GRM dose; thus, Cushing'ssyndrome patients receiving mifepristone treatment may be particularlyat risk of developing hypokalemia after initiating mifepristonetreatment, or after an increase in their mifepristone dose.

Applicant discloses herein methods for identifying patients at risk fordeveloping hypokalemia before their potassium levels drop below thenormal range; that is, these methods are directed to Cushing's syndromepatients with normal potassium levels. These methods thus may preventthe development of, or may reduce the severity of, or duration of,hypokalemia. The methods disclosed herein provide improved methods foridentifying and for monitoring patients at risk for developinghypokalemia. The methods disclosed herein provide improved methods forpreventing the development of hypokalemia in Cushing's syndromepatients, including methods for preventing the development ofhypokalemia in Cushing's syndrome patients treated with a GRM such asmifepristone. Thus, in embodiments, the present methods are directed toidentifying GRM-treated (e.g., mifepristone-treated) Cushing's syndromepatients at risk for developing hypokalemia; for monitoring suchpatients at risk for developing hypokalemia; for prophylacticallytreating such patients at risk for developing hypokalemia; forpreventing hypokalemia in such patients; and for reducing the durationor severity of hypokalemia in such patients.

While prior publications may describe certain relationships between ACTHand cortisol and hypokalemia, there is no report prior to this inventionthat establishes a direct correlation between serum ACTH or cortisollevel and the likelihood of developing hypokalemia at a later time amongCushing's syndrome patients undergoing or about to undergo GRMtreatment. For example, a 2012 publication by Auchus et al. (TheEndocrine Society's 94^(th) Annual Meeting and Expo, Jun. 23-26, 2012,Houston Tex.) indicates that higher 24-hour urinary free cortisol (UFC)levels (i.e., not plasma or serum concentrations of cortisol) in apatient prior to the start of mifepristone treatment tends to indicate ahigher likelihood of the patient developing hypokalemia followingmifepristone treatment. Measuring UFC has significant drawbacks as adiagnostic method: it takes 24-hours to complete the collection.Further, only a small and variable fraction of circulating cortisol isexpelled in urine, which means UFC levels can vary widely depending onfluid intake, the efficiency of the patient's kidney function, and otherfactors, so that UFC is not a clear or reliable indicator of circulatingcortisol. It is the circulating cortisol that is active and that mayaffect blood potassium levels, blood pressure, and other physiologicalvariables, not urinary cortisol. Moreover, it is not clear whether, orhow, mifepristone treatment may affect the fraction of circulatingcortisol that is expelled in the urine. Thus, UFC measurements provideonly an indirect, erratic, and unreliable indication of the activecortisol levels that may affect patient health, in contrast to measuringcortisol levels directly in the patient's plasma or serum samples (wherethe excess circulating cortisol that is causing the patient's disease isactive), which can be completed in less than an hour, is more sensitive,and not affected by kidney function.

Similarly, although it is well known in the field of Cushing's syndromeresearch that biologically active forms of ACTH can cause the body toproduce cortisol and so lead to increased cortisol levels and, in somecases, hypokalemia, it is also well known that the tumors, of bothectopic and pituitary origins, that cause Cushing's syndrome secrete anunpredictable, but sometimes significant, portion of ACTH that isbiologically inert, which leads to a level of dissociation between theamount and activity of ACTH in Cushing's syndrome patients. Furthermore,ACTH-producing tumors in Cushing's syndrome patients vary significantlyin size and in their efficiency of ACTH secretion in general and inresponse to cortisol. Thus, it was not believed before this inventionthat one could use ACTH or cortisol level in a Cushing's syndromepatient as a reliable indicator of the risk of future development ofhypokalemia. This view is expressed in publications such as the 2002Torpy et al. publication (Ann. N. Y. Acad. Sci. 970:134-144): “There wasno relation between ACTH level and hypokalemia” (see abstract on page135).

Accordingly, the present inventor has made surprising discoveries that,under specific circumstances, ACTH and cortisol levels can serve asreliable indicators of a Cushing's syndrome patient's risk of developinghypokalemia and discloses herein methods for identifying Cushing'ssyndrome patients who may be at risk for developing hypokalemia. Forexample, Applicant discloses herein methods for identifying Cushing'ssyndrome patients receiving mifepristone treatment who may be atincreased risk for developing hypokalemia. Applicant discloses hereinmethods for prophylactically treating for hypokalemia such Cushing'ssyndrome patients identified as being at risk for developinghypokalemia. Applicant discloses herein methods for prophylacticallytreating for hypokalemia such Cushing's syndrome patients who may be atrisk for developing hypokalemia. Applicant discloses herein methods forpreventing the development of, or reducing the severity of, hypokalemiain Cushing's syndrome patients identified as being at risk fordeveloping hypokalemia. Applicant discloses herein methods forpreventing the development of, or reducing the severity of, hypokalemiain Cushing's syndrome patients who may be at risk for developinghypokalemia.

Mifepristone may be administered (e.g., once daily) to a subjectsuffering from Cushing's syndrome, such as ACTH-dependent Cushing'ssyndrome. In embodiments, ACTH-dependent Cushing's syndrome patientsreceiving mifepristone are at risk of developing hypokalemia,particularly after an increase in their mifepristone dose. In any or allof the methods disclosed herein, Cushing's syndrome patients includepatients suffering from ACTH-dependent Cushing's; the Cushing's syndromepatient may be an adult suffering from endogenous Cushing's syndrome;may suffer from hyperglycemia secondary to hypercortisolism; may not bea candidate for surgery for Cushing's syndrome; may have failed surgeryfor Cushing's syndrome (i.e., Cushing's syndrome and/or its symptoms maypersist following surgery for Cushing's syndrome); and combinationsthereof. In embodiments, the patient is not otherwise in need of GRMtreatment; e.g., the patient is not otherwise in need of mifepristonetreatment.

Methods for treating a subject suffering from Cushing's syndrome, suchas, e.g., ACTH-dependent Cushing's syndrome and at risk for hypokalemiaresulting from GRM administration (e.g., following initiation of GRMtreatment or following an increase in GRM dose during continued GRMtreatment) are presented. In embodiments, methods for controllinghyperglycemia secondary to hypercortisolism in a Cushing's syndromepatient are disclosed. In embodiments, methods for reducing the risk ofdevelopment of hypokalemia in such a patient are disclosed. Inembodiments, methods for treating an adult patient with endogenousCushing's syndrome having type 2 diabetes mellitus or glucoseintolerance to control hyperglycemia secondary to hypercortisolism andof reducing the risk of development of hypokalemia in said patient aredisclosed. In embodiments, such a patient has failed surgery, or is nota candidate for surgery, for Cushing's syndrome.

Applicant has determined that increased risk of developing hypokalemiain ACTH-dependent Cushing's patients with normal blood potassium levelsmay be identified by determining whether or not blood ACTH levels riseexcessively following initial administration of a GRM or following anincreased dose of GRM during continued GRM treatment. Blood ACTH levelsmay be determined, for example, by measurements of serum obtained from apatient in the morning (morning serum ACTH). Similarly, ACTH can also bemeasured in a plasma sample taken from a patient according to methodsknown in the art. In addition, Applicant discloses that increased riskof developing hypokalemia in Cushing's syndrome patients, such as, e.g.,ACTH-dependent Cushing's patients with normal blood potassium levels maybe identified by determining whether or not cortisol levels are highprior to initiation of GRM treatment for Cushing's syndrome (e.g., forhyperglycemia secondary to hypercortisolism in a Cushing's syndromepatient). Cortisol levels may be determined, e.g., by measuring cortisolin blood (e.g., serum or plasma), urine, or saliva. In embodiments,cortisol levels may be measured in serum samples obtained in the morning(morning serum cortisol). Plasma samples may be used in a similarfashion to assess cortisol level in a subject.

Applicant further discloses methods for preventing hypokalemia in apatient suffering from ACTH-dependent Cushing's syndrome, the methodscomprising administering treatment for hypokalemia in a patient withnormal potassium level if the ratio of the level of ACTH following GRMadministration compared to the baseline level of ACTH (determined priorto GRM administration) is greater than a threshold level. The methodsfurther comprise administering treatment for hypokalemia in a patientwith normal potassium level if the ratio of the level of cortisolfollowing GRM administration compared to the baseline level of cortisol(determined prior to GRM administration) is greater than a thresholdlevel. The methods further comprise administering treatment forhypokalemia in a patient with normal potassium level if the ratio of thelevel of cortisol following GRM administration compared to the ACTHlevel following GRM administration) is greater than a threshold level.

For example, in embodiments, a threshold level for cortisol above whichindicates risk of developing hypokalemia is about 700 nmol/L cortisol,or about 750 nmol/L cortisol, or about 800 nmol/L cortisol (which isalso expressed as about 25 micrograms per deciliter, about 27 microgramsper deciliter, or about 29 micrograms per deciliter of cortisol,respectively), where cortisol is measured in serum samples taken in themorning. In preferred embodiments, such cortisol measurements areobtained from subjects who have not yet begun receiving glucocorticoidreceptor modulator (GRM) treatment for Cushing's syndrome; e.g., priorto beginning mifepristone treatment for Cushing's syndrome. Inembodiments of the methods disclosed herein, Cushing's patients who havenot yet begun receiving mifepristone treatment and whose morning serumcortisol is at or above threshold (e.g., at or above 750 nmol/L) areadministered prophylactic treatment for hypokalemia (e.g., areadministered a mineralocorticoid receptor antagonist such as, e.g.,spironolactone, or are administered supplemental potassium, or both). Infurther embodiments, cortisol is measured in saliva, or in urine (e.g.,urinary free cortisol, such as 24-hour urinary cortisol). Inembodiments, the threshold level for salivary cortisol is about 34nmol/L. For example, in further embodiments of the methods disclosedherein, Cushing's patients who have not yet begun receiving mifepristonetreatment and whose morning salivary cortisol is at or above threshold(e.g., at or above 34 nmol/L) are administered prophylactic treatmentfor hypokalemia (e.g., are administered a mineralocorticoid receptorantagonist such as, e.g., spironolactone, or are administeredsupplemental potassium, or both).

For example, in embodiments, a threshold level for ACTH above whichindicates risk of developing hypokalemia is about 110 pg/mL, or about112 pg/mL ACTH, or about 115 pg/mL, where ACTH is measured in serumsamples taken in the morning. In preferred embodiments, such ACTHmeasurements are obtained from subjects who have been receivingglucocorticoid receptor modulator (GRM) treatment for Cushing'ssyndrome; e.g., from subjects treated with mifepristone for two weeksprior to measurement of morning serum ACTH. In embodiments of themethods disclosed herein, Cushing's patients who have been receivingmifepristone treatment for two weeks and whose morning serum ACTH is ator above threshold (e.g., at or above 120 pg/mL) are administeredprophylactic treatment for hypokalemia (e.g., are administered amineralocorticoid receptor antagonist such as, e.g., spironolactone, orare administered supplemental potassium, or both).

In Cushing's syndrome patients determined to have excessive ACTH, orexcessive cortisol, or both, Applicant further discloses thatadministration of potassium, potassium sparing diuretics (e.g.,spironolactone), or other hypokalemia treatment before symptoms ofhypokalemia appear may reduce the risk of development of hypokalemia inthose patients. In embodiments, administration of a hypokalemiatreatment before symptoms of hypokalemia appear may prevent thedevelopment of, or reduce the severity of, hypokalemia in a Cushing'ssyndrome patient (e.g., an ACTH-dependent Cushing's syndrome patient,such as an adult patient suffering from hyperglycemia secondary tohypercortisolism due to endogenous Cushing's syndrome, and including anadult patient suffering from hyperglycemia secondary to hypercortisolismdue to endogenous Cushing's syndrome and having type 2 diabetes orglucose intolerance) otherwise at risk of developing hypokalemiafollowing an increase in GRM dose. In embodiments, the GRM ismifepristone.

Applicant has determined that the risk of developing hypokalemia inCushing's syndrome patients, such as ACTH-dependent Cushing's patients,with normal blood potassium levels may be identified by determiningwhether or not morning serum ACTH levels are excessive following GRMtreatment (e.g., following initiation of GRM treatment or following anincrease in GRM dose during continued GRM treatment). In embodiments,the GRM is mifepristone, and excessive ACTH rise is determined if themorning serum ACTH level is at or above about 110 pg/mL, e.g., at orabove 112 pg/mL, following mifepristone treatment for a time, such asfor two weeks, at a mifepristone dose (e.g., 300 mg mifepristone perday, or 600 mg mifepristone per day, or 900 mg mifepristone per day, or1200 mg mifepristone per day). In embodiments, Cushing's syndromepatients, such as ACTH-dependent Cushing's patients, with normal bloodpotassium levels, are at risk of developing hypokalemia if their bloodACTH levels are above about 112 pg/mL following an increase in GRM dose.In embodiments, the GRM is mifepristone, and excessive ACTH rise isdetermined if the ACTH level in blood rises above about 112 pg/mLfollowing an increase in GRM dose (e.g., administration of a once-dailydose of 600 mg mifepristone after the patient has been receiving 300 mgmifepristone once daily, or administration of a once-daily dose of 900mg mifepristone after the patient has been receiving 600 mg mifepristoneonce daily, or administration of a once-daily dose of 1200 mgmifepristone after the patient has been receiving 900 mg mifepristoneonce daily). The methods disclosed herein allow the identification ofpatients at risk for developing hypokalemia, e.g., during treatment forCushing's syndrome or related conditions, without the need to directlymonitor the patient's potassium levels. However, in some cases, themethods further comprise measuring a potassium level of the patient,e.g., in the blood of a patient (such as in a morning serum sampleobtained from the patient).

Accordingly, Applicant discloses methods for determining, prior toinitiating GRM treatment, whether or not a patient suffering fromCushing's syndrome (e.g., ACTH-dependent Cushing's syndrome) is at riskfor developing hypokalemia. In embodiments, the patient has morningserum cortisol levels at or above about 700 nmol/L prior to beginningGRM treatment for Cushing's syndrome. In embodiments, the morning serumcortisol level is at or above 750 nmol/L prior to beginning GRMtreatment for Cushing's syndrome. In embodiments, the GRM ismifepristone. In embodiments, the mifepristone dose for the treatment ofCushing's syndrome is 300 mg mifepristone; or 600 mg mifepristone; or900 mg mifepristone; or 1200 mg mifepristone. In embodiments, themifepristone dose is a once-daily dose. In embodiments, the patient hasnormal blood potassium levels prior to an increase in mifepristone dose.

Accordingly, Applicant discloses methods for determining whether or nota patient suffering from Cushing's syndrome (e.g., ACTH-dependentCushing's syndrome) is at risk for developing hypokalemia due to GRMtreatment (e.g., following initiation of GRM treatment or following anincrease in GRM dose during continued GRM treatment). In embodiments,the patient has morning serum ACTH levels at or above about 100 pg/mLACTH following GRM treatment for a time. In embodiments, the morningserum ACTH level is at or above 112 pg/mL ACTH following GRM treatmentfor a time. In embodiments, the GRM is mifepristone. In embodiments, themifepristone dose comprises an increase in the mifepristone dose to adose of 600 mg mifepristone after the patient has been receiving 300 mgmifepristone per day; or to a dose of 900 mg mifepristone after thepatient has been receiving 600 mg mifepristone per day; or to aonce-daily dose of 1200 mg mifepristone after the patient has beenreceiving 900 mg mifepristone per day. In embodiments, the mifepristonedose is a once-daily dose. In embodiments, the patient has normal bloodpotassium levels prior to an increase in mifepristone dose.

The methods disclosed herein allow the identification of patients atrisk for developing hypokalemia, e.g., during treatment for Cushing'ssyndrome or related conditions, and provide methods for prophylacticallytreating the patient for hypokalemia effective to reduce the risk ofdeveloping hypokalemia, or effective to reduce the severity ofhypokalemia in the patient, or to reduce the duration of hypokalemia inthe patient. The present methods provide such identification, and suchprophylactic treatments, without the need to directly monitor thepatient's potassium levels (although potassium levels may be monitoredif desired). The present methods avoid the potentially dangerouspractice of prophylactically pre-treating every patient for the risk ofhypokalemia; such treatment in a patient not at risk for hypokalemiacould lead to serious consequences (e.g., development of hyperkalemia, apotentially life-threatening condition, or adrenal insufficiency, orother serious condition). Accordingly, the present methods provide theadvantage of reducing the risk of developing a serious medical condition(hypokalemia) in patient identified as being at high risk for thatcondition, while avoiding unnecessary and potentially dangeroustreatment of patients who are not at high risk for that condition.

In one particular aspect, the present invention provides a novel methodfor therapeutic or prophylactic treatment of a patient who may developor is at a heightened risk of later developing hypokalemia, due to thepatient having been given or being scheduled to receive treatment forCushing's syndrome or related conditions by administration of a GRM. Themethod includes the step of administering to the patient an effectiveamount of a therapeutic agent for the condition of hypokalemia, thepatient being defined as a patient (especially an adult patient) withendogenous Cushing's syndrome having type 2 diabetes mellitus or glucoseintolerance to control hyperglycemia secondary to hypercortisolism, (1)who has received or is scheduled to receive treatment by administrationof a GRM, such as mifepristone; and (2) whose ACTH or cortisol level(e.g., serum or plasma level), after at least having GRM administrationonce or prior to receiving any GRM administration, respectively, hasbeen measured and shown to elevate above a pre-determined threshold forACTH or cortisol level. More specifically, the measurement of cortisollevel prior to the start or initiation of GRM treatment is particularlyuseful for treating/preventing the early onset type of hypokalemia: forexample, if a patient who is scheduled to receive GRM administration hasbeen detected to have a morning serum level of at least or above about750 nmol/L (or about 27 μg/dl) cortisol before the GRM administration,the patient is deemed at heighten risk of developing hypokalemia afterthe initiation of GRM administration (e.g., within the first two weeksof the start of GRM administration) and is therefore given an effectiveamount of a therapeutic agent for the condition of hypokalemiaconcurrently with the GRM administration as it is initiated. On theother hand, the measurement of ACTH after the start of GRMadministration (e.g., a week or two weeks after the initial GRMadministration started and has been ongoing) and before a doseescalation of GRM is particularly useful for treating/preventing thelate onset type of hypokalemia: for example, if a patient has been givenGRM treatment for about two weeks and is about to receive an increaseddose of GRM (dose escalation), and the patient has been detected to havea morning serum level of ACTH of at least or above about 112 pg/ml, thepatient is deemed at heighten risk of developing hypokalemia after thedose escalation of GRM administration and is therefore given aneffective amount of a therapeutic agent for the condition of hypokalemiaprior to or concurrently with the increased dose of GRM administration.In some cases, the patient being given hypokalemia medication to reducethe risk of or to prevent development of the late onset type ofhypokalemia has been previously tested and found to have no increasedrisk for the early onset type of hypokalemia and thus has not beenprophylatically treated for the early onset type of hypokalemia.Typically, the patients receiving prophylactic treatment for hypokalemiado not have lower than normal blood potassium level prior to the startof the prophylactic treatment.

In some embodiments of this invention, the GRM is mifepristone (alsoknown as RU-486, RU486, RU38.486) the chemical name of which is:11β-(4-dimethylaminophenyl)-17β-hydroxy-17α-(1-propynyl)-estra-4,9-dien-3-one),also written as17-beta-hydroxy-11-beta-(4-dimethyl-aminophenyl)-17-alpha-(1-propynyl)-estra-4,9-dien-3-one).In some embodiments, the patient's ACTH level is measured in a bloodsample (especially a plasma or serum sample), a saliva sample, or aurine sample. In some embodiments, the patient's cortisol level ismeasured in a blood sample (especially a plasma or serum sample), asaliva sample, or a urine sample. The sample used in measuring cortisollevel may be taken from the patient before the first dose of GRMadministration. The sample used in measuring ACTH level may be takenfrom the patient after at least one dose of GRM administration: forexample, after a first daily dose of GRM administration (e.g.,mifepristone administration) at 300 mg/day, 600 mg/day, or 900 mg/day, asample is taken before the second dose is given to the patient, e.g.,within 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 days or up to 2 weeks after thefirst GRM administration, but before a second, typically higher, dailydose of GRM (e.g., mifeprisone) administration, for example, after 600mg/day, 900 mg/day, or 1200 mg/day of mifepristone having beenadministered. In some embodiments, the first dose at about 300 mg/day ofa GRM such as mifepristone is administered to a patient; after about7-21 days, for example, about 2 weeks, of administration at this firstdose, the patient is set to enter a second phase of treatment and toreceive a second and higher dose of GRM (such as mifepristone) at about600 mg/day, it is at this conjuncture that the patient's risk ofdeveloping hypokalemia is assessed based on the patient's ACTH level andthe patient is treated as appropriate in accordance with the methodsdescribed herein.

Due to the nature of ACTH or cortisol presence in a patient's tissuesample and bodily fluids, the determination of a potential increase inACTH or cortisol level typically requires samples of the same type(e.g., serum samples) and samples taken from the patients and standardcontrol subjects at about the same time during the day (e.g., in themorning at about 6 AM, 8 AM, 10 AM, or in the afternoon at about 12 PM,2 PM, 4 PM, or 6 PM of the day).

In some embodiments, the post-GRM administration level of ACTH ismeasured to be at least about 100% higher than a standard control oraverage normal value (or at least twice the standard control or averagenormal value), i.e., the ACTH level found in samples of the same typetaken from normal subjects. In some embodiments, the post-GRMadministration level of ACTH is measured to be at least about 80, 100,108, 110, 112, 115, or 120 pg/ml or higher in a plasma or serum sampletaken from the patient in the morning (e.g., between about 6 AM to about10 AM, for example, at about 7, 8, or 9 AM). In some embodiments, thepatient's cortisol level has been measured prior to the start of GRMadministration, and the pre-GRM administration level of cortisol ismeasured to be at least about 100% higher than a standard control oraverage normal value (or at least twice the standard control or averagenormal value), i.e., the cortisol level found in samples of the sametype taken from normal subjects. In some embodiments, the pre-GRMadministration level of cortisol is measured to be at least about 700,750, or 800 nmol/L (about 25, 27, or 29 μg/dl, respectively) or higherin a plasma or serum sample taken from the patient in the morning (e.g.,between about 6 AM to about 10 AM, for example, at about 7, 8, or 9 AM).

In some embodiments, the patient suitable for receiving the treatmentmethod of this application is an adult who may be of either gender andwho is in his/her 20s, 30s, 40s, 50s, 60s, 70s, 80s or older, forexample, between the ages of about 20-30, 30-40, 40-50, 50-60, 60-70,70-80, or 80 or 85 and above. In some embodiments, the patient is onewho is without any symptoms of hypokalemia and is not otherwise in needof treatment by any medication for hypokalemia.

The methods disclosed herein provide the surprising advantages ofreduced risk of, reduced occurrence, and prevention, of hypokalemia inCushing's syndrome patients treated with mifepristone. Furtheradvantages include the use of plasma levels of ACTH and cortisol asindicators, which are quicker and more consistent measures of patientstatus than, for example, urinary free cortisol (which requires 24 hoururine collection). On the other hand, the methods disclosed herein alsoallow physicians to identify those among Cushing's syndrome patients whodo not have elevated risk of developing hypokalemia upon beginning toreceive GRM administration or upon receiving an increased dose of GRMadministration, and who therefore do not need to be given anyprophylactic treatment for hypokalemia such that any unnecessaryside-effects of such prophylactic treatment, which can belife-threatening, can be avoided.

The methods disclosed herein provide the advantages of reduced risk of,reduced duration and severity of, delayed onset of, and/or completeprevention of, hypokalemia and hypokalemia-associated symptoms,including reducing the risk or, or prevention of, arrhythmias, suddencardiac arrest, and other life-threatening symptoms associated withhypokalemia. Further symptoms associated with hypokalemia which may beprevented, or reduced by the present methods include, e.g., fatigue;edema; hypertension; muscle weakness, cramps, or muscle spasms;neurological problems including paresthesia and paralysis; renalproblems such as polyuria, polydipsia, and nocturia; gastrointestinaldisorders including abdominal cramps, constipation, nausea, andvomiting; long Q-T syndrome; cardiac palpitations and arrhythmias. Theyalso help physicians avoid unnecessary prophylactic treatment forhypokalemia, which can cause serious adverse events. These advantagessurprisingly improve patient outcomes, avoid serious risks associatedwith mifepristone treatment for Cushing's syndrome, and provide treatingphysicians with new and improved tools for management of mifepristonetreatment of Cushing's syndrome.

In summary, the present invention provide new methods for assessing therisk or likelihood of developing hypokalemia at a later time in apatient, especially an adult patient with endogenous Cushing's syndromehaving type 2 diabetes mellitus or glucose intolerance to controlhyperglycemia secondary to hypercortisolism who has received or isscheduled to receive treatment by administration of a glucocorticoidreceptor modulator (GRM) (such as mifepristone), based on (1) detectingan above-threshold level of serum or plasma ACTH found in a blood sampletaken from the patient after the initial GRM administration (forexample, 1 or 2 weeks after the initial and continuous GRMadministration at a lower dosage) but before subsequent GRMadministration of an increased dosage; or (2) detecting anabove-threshold level of serum or plasma cortisol found in a bloodsample taken from the patient prior to the start of GRM administration.Upon identifying a patient who has a heightened risk of later developinghypokalemia even though who has not yet manifested any symptom of thecondition, the present invention further provides novel methods forprophylactically treating the patient by administration of one or moretherapeutically active agents for the condition in an effective amountto delay onset of hypokalemia, or reduce severity/duration ofhypokalemia, or completely prevent occurrence of hypokalemia: in thecase of (1), the patient receives an effective amount of a therapeuticagent for hypokalemia concurrently started or co-administered with theincreased dose of a GRM, and may continue to receive the therapeuticagent continuously along with the higher dose of GRM. In the case of(2), the patient receives an effective amount of a therapeutic agent forhypokalemia concurrently started or co-administered with the initialdose of a GRM, and may continue to receive the therapeutic agentcontinuously along with the GRM administration.

For instance, to identify patients at high risk of developinghypokalemia following GRM initiation, measure morning serum cortisolprior to starting GRM treatment. If serum cortisol is above about 27μg/dL, prophylactic therapy (e.g., with mineralocorticoid antagonists)should be initiated concurrently with GRM administration. To identifypatients at high risk of developing hypokalemia following an increase inthe dose of GRM treatment, about two weeks after starting GRM treatment(e.g., at about 7 to about 21 days, such as about 14 days), measuremorning ACTH levels. If ACTH levels are above about 112 pg/mL,prophylactic treatment for hypokalemia (e.g., with mineralocorticoidantagonists) should be initiated or intensified before the dose of GRMis increased.

The present methods provide the advantages of a) reducing the risk ofdeveloping, and preventing, hypokalemia in Cushing's syndrome patientsreceiving GRM treatment, by prophylactic administration of hypokalemiatreatment before the patient's potassium drops below normal levels,avoiding the serious and potentially life-threatening symptoms ofhypokalemia; and b) by identifying those patients at high risk, avoidingunnecessary administration of hypokalemia treatments to patients who arenot at high risk of hypokalemia, thus avoiding the risk of (iatrogenic)hyperkalemia, which has its own serious side effects.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows plasma ACTH (pg/mL) over the course of study (study days 0to 210) for two groups of Cushing's patients who received mifepristoneat doses of 300 mg/day (days 0 to 13); 600 mg/day (days 14 to 41); 900mg/day (days 42 to 69); and 1200 mg/day (days 70 onward). The firstgroup (lower line) had blood potassium levels that remained within thenormal range. The second group (upper line) experienced low potassiumlevels (less than or equal to 3.5 mEq/L): their blood potassium levelswere below the normal range. Note that the hypokalemic patients hadplasma ACTH levels that exceeded 100 pg/mL when the mifepristone dosewas increased by 300 mg/day; i.e., from 300 mg/day to 600 mg/day, andwhich remained above that level for the duration of the study. Incontrast, those Cushing's patients who did not experience hypokalemiahad plasma ACTH levels which remained near 100 pg/mL, and did not showdramatic rises in ACTH levels when the mifepristone dose was raised by300 mg/day (the plasma ACTH level of these patients did not show abruptincreases when the mifepristone dose was raised from 300 mg/day to 600mg/day; nor when it was raised from 600 mg/day to 900 g/day; nor when itwas raised from 900 mg/day to 1200 g/day). FIG. 1 shows the associationbetween ACTH levels and potassium (<3.5 mmol/L, ≥3.5 mmol/L). It showsthat patients with potassium levels <3.5 mmol/L had on average higherACTH levels on the same study day.

FIG. 2 demonstrates the association between levels of potassium (<3.5mEq/L, ≥3.5 mEq/L) and Total Cortisol levels. It shows that patientswith potassium levels <3.5 mEq/L had on average higher Total Cortisollevels on the same study day.

FIG. 3 ROC Curve for Association between Total Serum Cortisol atBaseline and Early-Onset Hypokalemia. Numbers on the corners of the ROCcurve correspond to Baseline (Day 1) Serum Cortisol levels.

FIG. 4 ROC Curve for Association between ACTH at Day 14 and SubsequentHypokalemia during Mifepristone Treatment.

DETAILED DESCRIPTION A. Introduction

Cushing's syndrome patients treated with a glucocorticoid receptormodulator (GRM) such as mifepristone may be at risk for developinghypokalemia. Hypokalemia was observed in 44% of Cushing's syndromepatients receiving mifepristone treatment. As disclosed herein,GRM-treated Cushing's syndrome patients that are at high risk ofdeveloping hypokalemia following GRM treatment initiation may beidentified by measuring morning serum cortisol prior to initiation ofthe GRM treatment. A morning serum cortisol level at or above athreshold level is indicative of high risk of developing hypokalemiaduring GRM treatment for Cushing's syndrome. In embodiments, thethreshold morning cortisol level measured prior to initiating GRMtreatment that is indicative of high risk of developing hypokalemiaduring GRM treatment for Cushing's syndrome is a morning serum cortisollevel that is at or above about 1.5 times normal morning serum cortisollevels; or that is at or above about 2 times, or about 2.5 times, orabout 3 times, normal morning serum cortisol levels (where normalmorning serum cortisol levels are determined by mean levels measured insamples obtained from multiple normal subjects). In embodiments, amorning serum cortisol level at or above a threshold level of 750 nmol/Lis indicative of high risk of developing hypokalemia during GRMtreatment for Cushing's syndrome. Patients whose morning serum cortisollevel is at or above the threshold level (e.g., at or above 750 nmol/Lor at or above about 2 times normal morning serum cortisol levels) priorto initiating GRM treatment should be given prophylactic treatment forhypokalemia concurrently with the GRM administration. Such prophylactictreatment may include administration of mineralocorticoid antagonists orother potassium-sparing diuretic; may include potassium supplementation(e.g., oral, intravenous, or other), or both.

Accordingly, Applicant discloses herein novel methods of reducing therisk of hypokalemia in Cushing's syndrome patients treated with aglucocorticoid receptor modulator (GRM), reducing the severity ofhypokalemia in Cushing's syndrome patients treated with a GRM, ofpreventing hypokalemia in Cushing's syndrome patients treated with aGRM, of identifying Cushing's syndrome patients at high risk ofdeveloping hypokalemia when being treated with a GRM, and othertreatment and identifying methods. The GR may be, e.g., mifepristone.Applicant has discovered that there are strong associations between thedevelopment of hypokalemia and 1) serum cortisol levels at baseline(prior to treatment with mifepristone), and 2) ACTH levels after 2 weeksof mifepristone administration. For example, early onset hypokalemia(appearing within the first 2 weeks of mifepristone treatment ofCushing's syndrome patients) is most correlated with high baseline serumcortisol levels (>750 nmol/L). For further example, late onsethypokalemia (appearing at or after 2 weeks of mifepristone treatment ofCushing's syndrome patients) has the strongest correlation with highACTH levels (≥112 pg/mL) after 2 weeks of treatment with mifepristone. Ayet further example is that severe and/or recurrent hypokalemia hasstrong correlation with high ACTH levels (≥112 pg/mL). (A patientsuffers from hypokalemia if their serum potassium level is less than 3.5milliequivalents per liter (mEq/L). A patient suffers from severehypokalemia if their serum potassium level is less than or equal to 2.5mEq/L. A patient suffers from recurrent hypokalemia if they suffer twoor more instances of hypokalemia, whether severe or not.)

As disclosed herein, GRM-treated Cushing's syndrome patients that are athigh risk of developing hypokalemia during GRM treatment may beidentified by measuring morning serum ACTH after starting the GRMtreatment (e.g., measured two weeks after starting the GRM treatment). Amorning serum ACTH level at or above a threshold level is indicative ofhigh risk of developing hypokalemia during GRM treatment for Cushing'ssyndrome. In embodiments, the threshold morning ACTH level measuredafter starting GRM treatment that is indicative of high risk ofdeveloping hypokalemia during GRM treatment for Cushing's syndrome is amorning serum ACTH level that is at or above about 1.5 times normalmorning serum ACTH levels; or that is at or above about 2 times, orabout 2.5 times, or about 3 times, normal morning serum ACTH levels(where normal morning serum ACTH levels are determined by mean levelsmeasured in samples obtained from multiple normal subjects). Inembodiments, the threshold morning ACTH level indicative of developinghypokalemia may be 1.5 time, or 2 times, or 2.5 times, or 3 times, thebaseline morning serum ACTH level (where baseline morning serum ACTHlevel is determined from at least one morning serum ACTH measurementfrom a sample obtained from the patient prior to beginning GRMadministration, or prior to increasing the GRM dose). In embodiments,the threshold morning ACTH level measured after starting GRM treatmentthat is indicative of high risk of developing hypokalemia during GRMtreatment for Cushing's syndrome is a morning serum ACTH level that isat or above 112 pg/mL. In embodiments, a morning serum ACTH level at orabove the threshold level (e.g., at or above about 2 times normal (orbaseline) morning serum ACTH levels, or at or above 112 pg/mL) measuredtwo weeks after initiation of GRM treatment is indicative of high riskof developing hypokalemia during GRM treatment for Cushing's syndrome.Patients whose morning ACTH levels are at or above the threshold levelwhen measured at a time after initiation of GRM treatment should begiven prophylactic treatment for hypokalemia. In embodiments, patientswhose morning ACTH levels are at or above the threshold level whenmeasured two weeks after initiation of GRM treatment should be givenprophylactic treatment for hypokalemia. Such prophylactic treatment mayinclude administration of mineralocorticoid antagonists or otherpotassium-sparing diuretic; may include potassium supplementation (e.g.,oral, intravenous, or other), or both.

In embodiments, such prophylactic treatment for hypokalemia may beadministered prior to GRM dose escalation where morning ACTH levels areat or above threshold (e.g., twice normal, or twice baseline, or 112pg/mL). For example, the morning ACTH levels of a patient receiving 300mg per day GRM may be measured, and if found to be at or abovethreshold, the patient may be administered prophylactic treatment forhypokalemia when the daily dose of GRM is increased to 600 mg/day. Forfurther example, the morning ACTH levels of a patient receiving 600 mgper day GRM may be measured, and if found to be at or above threshold,the patient may be administered prophylactic treatment for hypokalemiawhen the daily dose of GRM is increased to 900 mg/day. For yet furtherexample, the morning ACTH levels of a patient receiving 900 mg per dayGRM may be measured, and if found to be at or above threshold, thepatient may be administered prophylactic treatment for hypokalemia whenthe daily dose of GRM is increased to 1200 mg/day. In embodiments, theGRM may be, e.g., mifepristone.

Accordingly, Applicant discloses methods for identifying patients atrisk for, and for prophylactically treating, hypokalemia inmifepristone-treated Cushing's syndrome patients. The methods disclosedherein can be used to treat a Cushing's syndrome patient; inembodiments, the Cushing's syndrome patient suffers from ACTH-dependentCushing's syndrome and is at risk for hypokalemia resulting fromincreased GRM dose. In embodiments, the patient is an adult havingendogenous Cushing's syndrome and suffering from hyperglycemia secondaryto hypercortisolism. In embodiments, the patient is an adult having type2 diabetes or glucose intolerance, having endogenous Cushing's syndromeand suffering from hyperglycemia secondary to hypercortisolism. Inembodiments, the patient may have failed surgery for Cushing's syndrome,or may not be a candidate for surgery for Cushing's syndrome. Inembodiments, the methods are suitable for controlling hyperglycemiasecondary to hypercortisolism in an adult patient suffering fromendogenous Cushing's syndrome and who has failed surgery for Cushing'ssyndrome, or is not a candidate for surgery for Cushing's syndrome. Inembodiments, the methods are suitable for controlling hyperglycemiasecondary to hypercortisolism in an adult with patient type 2 diabetesor glucose intolerance and suffering from endogenous Cushing's syndrome,who has failed surgery for Cushing's syndrome, or is not a candidate forsurgery for Cushing's syndrome.

Applicant discloses herein the surprising discovery that increased riskof developing hypokalemia in ACTH-dependent Cushing's patients may beidentified by determining whether or not ACTH levels, or cortisollevels, or both, rise excessively following an increase in GRM dose.Administration of potassium, spironolactone, or other hypokalemiatreatment before symptoms of hypokalemia appear in the patient, based onsuch determination of excessive rise in ACTH or cortisol, may reduce therisk of development of hypokalemia in those patients, and may preventthe development of, or reduce the severity of, hypokalemia in aCushing's syndrome patient (e.g., an ACTH-dependent Cushing's syndromepatient) otherwise at risk of developing hypokalemia following anincrease in GRM dose. In embodiments, the GRM is mifepristone.

As disclosed above, in embodiments, the threshold morning ACTH levelindicative of increased risk of developing hypokalemia may be 112 pg/mL.In embodiments, the risk of developing hypokalemia in such patients maybe identified by determining whether or not morning serum ACTH levelsrise above a threshold level of about 100 pg/mL (e.g., 112 pg/ml)following initiation of mifepristone treatment or following an increasein GRM dose, where the GRM may be mifepristone; e.g., determiningwhether or not morning serum ACTH levels rise above about 100 pg/mL(e.g., 112 pg/ml) following initiation of mifepristone treatment orfollowing an increase in mifepristone dose. In embodiments, the increasein mifepristone dose is following initiation of mifepristone treatment,or is an increase from a once-daily dose of 300 mg mifepristone per dayto a once-daily dose of 600 mg mifepristone; or from a once-daily doseof 600 mg mifepristone to 900 mg mifepristone once daily; or from aonce-daily dose of 900 mg mifepristone to 1200 mg mifepristone oncedaily. In embodiments, the threshold morning serum ACTH level is 112pg/mL. In embodiments, the threshold morning serum ACTH level is about100 pg/ml, or about 105 pg/ml, or about 110 pg/mL, or about 115 pg/mL,or about 120 pg/mL.

As disclosed above, in embodiments, the threshold morning ACTH levelindicative of increased risk of developing hypokalemia may be 1.5 times,or 2 times, or 2.5 times, or 3 times the normal morning serum ACTH level(where normal morning serum ACTH levels are determined by mean levelsmeasured in samples obtained from multiple normal subjects). Inembodiments, the threshold morning ACTH level indicative of developinghypokalemia may be 1.5 time, or 2 times, or 2.5 times, or 3 times, thebaseline morning serum ACTH level (where baseline morning serum ACTHlevel is determined from at least one morning serum ACTH measurementfrom a sample obtained from the patient prior to beginning GRMadministration, or prior to increasing the GRM dose). In embodiments,the risk of developing hypokalemia in such patients may be identified bydetermining whether or not morning serum ACTH levels rise above athreshold level of about 1.5 times, or 2 times, or 2.5 times, or 3 timesthe normal (or baseline) morning serum ACTH level following an increasein GRM dose, where the GRM may be mifepristone; e.g., determiningwhether or not morning serum ACTH levels rise above about 1.5 times, or2 times, or 2.5 times, or 3 times the normal morning serum ACTH levelfollowing initiation of mifepristone treatment or following an increasein mifepristone dose. In embodiments, the increase in mifepristone doseis from a once-daily dose of 300 mg mifepristone per day to a once-dailydose of 600 mg mifepristone; or from a once-daily dose of 600 mgmifepristone to 900 mg mifepristone once daily; or from a once-dailydose of 900 mg mifepristone to 1200 mg mifepristone once daily.

In further embodiments, the risk of developing hypokalemia in suchpatients may be identified by determining whether or not cortisol levelsare above a threshold level prior to initiation of GRM treatment, orrise above a threshold level following an increase in GRM dose; e.g.,determining whether or not cortisol levels are above a threshold levelprior to initiation of mifepristone treatment, or rise above a thresholdlevel following an increase in mifepristone dose, where the cortisollevels may be measured from blood samples, urine samples, salivasamples, or combinations thereof. In embodiments, the increase inmifepristone dose is from a once-daily dose of 300 mg mifepristone perday to a once-daily dose of 600 mg mifepristone; or from a once-dailydose of 600 mg mifepristone to 900 mg mifepristone once daily; or from aonce-daily dose of 900 mg mifepristone to 1200 mg mifepristone oncedaily. In embodiments, the threshold level is a morning serum cortisollevel of about 700 nmol/L (25 μg/dL), or about 750 nmol/L (27 μg/dL), orabout 800 nmol/L (29 μg/dL). In embodiments, the threshold morningcortisol level indicative of increased risk of developing hypokalemiamay be 1.5 times, or 2 times, or 2.5 times, or 3 times the normalmorning serum cortisol level (where normal morning serum cortisol levelsare determined by mean levels measured in samples obtained from multiplenormal subjects). In embodiments, the threshold morning cortisol levelindicative of developing hypokalemia may be 1.5 time, or 2 times, or 2.5times, or 3 times, the baseline morning serum cortisol level (wherebaseline morning serum cortisol level is determined from at least onemorning serum cortisol measurement from a sample obtained from thepatient prior to beginning GRM administration, or prior to increasingthe GRM dose).

Applicant has determined that increased risk of developing hypokalemiain ACTH-dependent Cushing's patients with normal blood potassium levelsmay be identified by determining whether or not blood ACTH levels riseexcessively following administration of an initial or an increased GRMdose. In Cushing's syndrome patients determined to have high levels ofACTH following initiation of GRM treatment, or following an increase inGRM dose; or determined to have high cortisol prior to administration ofGRM, or both, Applicant further discloses that administration ofpotassium, spironolactone, or other hypokalemia treatment beforesymptoms of hypokalemia appear may reduce the risk of development ofhypokalemia in those patients. In embodiments, administration ofpotassium, or spironolactone, or other hypokalemia treatment beforesymptoms of hypokalemia appear may prevent the development of, or reducethe severity of, hypokalemia in a Cushing's syndrome patient (e.g., anACTH-dependent Cushing's syndrome patient) otherwise at risk ofdeveloping hypokalemia following an increase in GRM dose. Inembodiments, the GRM is mifepristone.

Applicant has determined that the risk of developing hypokalemia inCushing's syndrome patients, such as ACTH-dependent Cushing's patients,with normal blood potassium levels may be identified by determiningwhether or not blood ACTH levels rise excessively following an increasein GRM dose. In embodiments, the GRM is mifepristone, and excessive ACTHrise is determined if the ACTH level in blood rises above about 100pg/mL (e.g., 112 pg/mL) following an increase in mifepristone dose(e.g., administration of a once-daily dose of 600 mg mifepristone afterthe patient has been receiving 300 mg mifepristone once daily, oradministration of a once-daily dose of 900 mg mifepristone after thepatient has been receiving 600 mg mifepristone once daily). Inembodiments, Cushing's syndrome patients, such as ACTH-dependentCushing's patients, with normal blood potassium levels, are at risk ofdeveloping hypokalemia if their blood ACTH levels are at or above about112 pg/mL following two weeks of GRM treatment at an initial or at anincreased GRM dose. In embodiments, the GRM is mifepristone, andexcessive ACTH rise is determined if the ACTH level in blood rises aboveabout 100 pg/mL (e.g., 112 pg/mL) following an increase in GRM dose(e.g., administration of a once-daily dose of 300 mg mifepristone fortwo weeks to a patient who has not previously received mifepristone, oradministration of a once-daily dose of 600 mg mifepristone after thepatient has been receiving 300 mg mifepristone once daily, oradministration of a once-daily dose of 900 mg mifepristone after thepatient has been receiving 600 mg mifepristone once daily). The methodsdisclosed herein allow the identification of patients at risk fordeveloping hypokalemia, e.g., during treatment for Cushing's syndrome orrelated conditions, without the need to directly monitor the patient'spotassium levels. However, in some cases, the methods further comprisemeasuring a potassium level of the patient, e.g., in the blood of apatient (such as in a blood sample obtained from the patient).

Accordingly, Applicant discloses methods for determining whether or nota patient suffering from Cushing's syndrome (e.g., ACTH-dependentCushing's syndrome) is at risk for developing hypokalemia following anincrease in the patient's GRM dose. In embodiments, the patient hasmorning serum ACTH levels at or above about 100 pg/mL ACTH following anincrease in the GRM dose. In embodiments, the morning serum ACTH levelis at or above about 112 pg/mL ACTH. In embodiments, the morning serumACTH level is at or above about 112 pg/mL ACTH following two weeks ofGRM treatment, or is at or above about 112 pg/mL ACTH following anincrease in the GRM dose. In embodiments, the GRM is mifepristone. Inembodiments, an increase in the mifepristone dose is a once-daily doseof 600 mg mifepristone after the patient has been receiving 300 mgmifepristone once daily; or a once-daily dose of 900 mg mifepristoneafter the patient has been receiving 600 mg mifepristone once daily; ora once-daily dose of 1200 mg mifepristone after the patient has beenreceiving 900 mg mifepristone once daily. In embodiments, the patienthas normal blood potassium levels prior to an increase in GRM dose.

B. Definitions

The following definitions are presented to aid in the understanding ofthe disclosure herein, and are not meant to be limiting.

A mineralocorticoid receptor (MR), also known as a type I glucocorticoidreceptor (GR I), is activated by aldosterone in humans.

The term “glucocorticosteroid” (“GC”) or “glucocorticoid” refers to asteroid hormone that binds to a glucocorticoid receptor.Glucocorticosteroids are typically characterized by having 21 carbonatoms, an α,β-unsaturated ketone in ring A, and an α-ketol groupattached to ring D. They differ in the extent of oxygenation orhydroxylation at C-11, C-17, and C-19; see Rawn, “Biosynthesis andTransport of Membrane Lipids and Formation of Cholesterol Derivatives,”in Biochemistry, Daisy et al. (eds.), 1989, pg. 567.

The term “cortisol” refers to the naturally occurring glucocorticoidhormone (also known as hydrocortisone) having the structure:

Cortisol is typically produced by the zona fasciculata of the adrenalgland.

As used herein, the term glucocorticoid receptor (GR) refers to anintracellular receptor that binds glucocorticoids, such as cortisol,dexamethasone, or other molecules. A glucocorticoid receptor, also knownas a corticosteroid receptor or as a type II glucocorticoid receptor (GRII), and in humans, as a cortisol receptor, is activated by cortisol inhumans (or, e.g., by corticosterone (“cortisone”) in some other animals,such as rats and mice). The human cortisol receptor (GR II receptor,Genbank: P04150) specifically binds to cortisol and/or cortisol analogs(e.g. dexamethasone). The term includes isoforms of GR II, recombinantGRII, and mutated GRIT.

As used herein, the term glucocorticoid receptor modulator (GRM) refersto an agent that affects the action of a glucocorticoid receptor (GR).Such modulation may include activation (agonist action), partialactivation (partial agonist action), inhibition (reduction in activationof the receptor under conditions where it would otherwise be activated,such as in the presence of cortisol), and blockade (complete or nearcomplete suppression of activation of the receptor under conditionswhere it would otherwise be activated, such as in the presence ofcortisol). GRMs may affect the activity of a GR by increasing or bydecreasing the activity of the GR. GRMs include steroids, includingmifepristone, and, in embodiments, include pyrimidinediones;azadecalins; fused-ring azadecalins; heteroaryl-ketone fused-ringazadecalins; and other compounds.

As used herein, the term “selective glucocorticoid receptor modulator”(SGRM) refers to any composition or compound which inhibits anybiological response associated with the binding of a GR to an agonist.By “selective,” the drug preferentially binds to the GR rather thanother intracellular receptors, such as the progesterone receptor (PR),the mineralocorticoid receptor (MR) or the androgen receptor (AR).

As used herein, the terms “glucocorticoid agonist”, “glucocorticoidreceptor agonist”, “glucocorticoid receptor type II agonist”, and “GRITagonist” refer to a compound or agent which may bind to and activate acortisol receptor. Such agents include, for example, cortisol,dexamethosone, prednisone, and other compounds and agents which bind toand activate a GRII.

As used herein, the terms “glucocorticoid antagonist”, “glucocorticoidreceptor antagonist”, “glucocorticoid antagonist”, “glucocorticoidreceptor type II antagonist”, “GRII antagonist”, and “GRA” refer toagents that inhibit the action of a cortisol receptor; such inhibitionmay include interfering with the binding of a glucocorticoid agonistsuch as cortisol, dexamethosone, or other compound or agent which maybind to and activate a cortisol receptor. A GRA is a glucocorticoidreceptor modulator. Inhibition constants (K_(i)) for GRAs against thehuman cortisol receptor may be between about 0.0001 nM and about 1,000nM; preferably may be between about 0.0005 nM and about 10 nM, and mostpreferably between about 0.001 nM and about 1 nM.

The terms “glucocorticoid receptor antagonist,” “GRA,” and“glucocorticoid receptor blocker” refer to any composition or compoundwhich partially or completely inhibits (antagonizes) the binding of aglucocorticoid receptor (GR) agonist, such as cortisol, or cortisolanalogs, synthetic or natural, to a GR. A “specific glucocorticoidreceptor antagonist,” “SGRA,” and “specific glucocorticoid receptorblocker” refer to any composition or compound which inhibits anybiological response associated with the binding of a GR to an agonist.By “specific,” we intend the drug to preferentially bind to the GRrather than another nuclear receptors, such as mineralocorticoidreceptor (MR) or progesterone receptor (PR).

As used herein, GRM, SGRM, and GRA compounds may be identified bybinding assays and functional assays (e.g., cell-based assays) known tothose of skill in the art. Preferred binding assays suitable for use inidentifying and characterizing GRM, SGRM, and GRA compounds aredisclosed, for example, in U.S. Pat. No. 7,928,237 (e.g., Section III,under the heading “Binding Assays”; and under the heading “Cell-BasedAssays”); in U.S. Pat. No. 8,685,973 (e.g., Section VI, under heading A:“Binding Assays” and under heading B, “Cell-Based Assays”); in U.S. Pat.No. 8,859,774 (e.g., Section VII, under heading A: “Binding Assays”; andunder heading B, “Cell-Based Assays”); and in U.S. Pat. No. 10,047,082(e.g., Section V, under heading A: “Binding Assays”; and under headingB, “Cell-Based Assays”). The contents of U.S. Pat. Nos. 7,928,237;8,685,973; 8,859,774; and 10,047,082 are hereby incorporated byreference herein in their entireties. In some embodiments,administration of a GRM, such as mifepristone, may lead to increase incortisol level in a patient.

Mifepristone is a GRM which binds to GRII (and which also binds to aprogesterone receptor). As used herein, the term “mifepristone” refersto11β-(4-dimethylaminophenyl)-17β-hydroxy-17α-(1-propynyl)-estra-4,9-dien-3-one),also referred to as RU486, or as RU38.486, or as17-beta-hydroxy-11-beta-(4-dimethyl-aminophenyl)-17-alpha-(1-propynyl)-estra-4,9-dien-3-one).Mifepristone binds to GR, typically with high affinity, and inhibits thebiological effects initiated/mediated by the binding of any cortisol orcortisol analogue to a GR receptor (and thus is a GRM that is a GRA).Salts, hydrates and prodrugs of mifepristone are all included in theterm “mifepristone” as used herein. Thus, used herein, “mifepristone”refers to the molecule that has the following structure:

and to salts, hydrates and prodrugs thereof, and pharmaceuticalcompositions thereof. Mifepristone is also sometimes abbreviated as“mife” and “MIFE”.

Metabolites of mifepristone include RU42633 (desmethylmifepristone:(8S,11R,13S,14S,17S)-17-hydroxy-13-methyl-11-[4-(methylamino)phenyl]-17-prop-1-ynyl-1,2,6,7,8,11,12,14,15,16-decahydrocyclopenta[a]phenanthren-3-one);RU42698 (22-hydroxy mifepristone:(8S,11R,13S,14S,17S)-11-[4-(dimethylamino)phenyl]-17-hydroxy-17-(3-hydroxyprop-1-ynyl)-13-methyl-1,2,6,7,8,11,12,14,15,16-decahydrocyclopenta[a]phenanthren-3-one);and RU42848 (didesmethylmifepristone:(8S,11R,13S,14S,17S)-11-(4-aminophenyl)-17-hydroxy-13-methyl-17-prop-1-ynyl-1,2,6,7,8,11,12,14,15,16-decahydrocyclopenta[a]phenanthren-3-one),among others.

In some embodiments, the GRM comprises a steroidal backbone with atleast one phenyl-containing moiety in the 11-β position of the steroidalbackbone. In some cases, the phenyl-containing moiety in the 11-βposition of the steroidal backbone is a dimethylaminophenyl moiety. Insome cases, the GRM is mifepristone. In some embodiments, the GRM isselected from the group consisting of11β-(4-dimethylaminoethoxyphenyl)-17α-propynyl-17β-hydroxy-4,9estradien-3-one and(17α)-17-hydroxy-19-(4-methylphenyl)androsta-4,9(11)-dien-3-one. In someembodiments, the GRM is(11β,17β)-11-(1,3-benzodioxol-5-yl)-17-hydroxy-17-(1-propynyl)estra-4,9-dien-3-one.

The term “steroidal backbone” in the context of glucocorticoid receptorantagonists containing such refers to glucocorticoid receptorantagonists that contain modifications of the basic structure ofcortisol, an endogenous steroidal glucocorticoid receptor ligand. Thebasic structure of a steroidal backbone is provided as Formula I:

The two most commonly known classes of structural modifications of thecortisol steroid backbone to create glucocorticoid antagonists includemodifications of the 11-β hydroxy group and modification of the 17-βside chain (See, e. g., Lefebvre (1989) J. Steroid Biochem. 33:557-563).

As used herein, the phrase “non-steroidal backbone” in the context ofglucocorticoid receptor antagonists containing such refers toglucocorticoid receptor antagonists that do not share structuralhomology to, or are not modifications of, cortisol. Such compoundsinclude, for example, small molecules, synthetic mimetics and analogs ofproteins, including partially peptidic, pseudopeptidic and non-peptidicmolecular entities.

In some embodiments, the GRM is a non-steroidal compound. Inembodiments, non-steroidal GRM compounds include compounds having acyclohexyl-pyrimidine backbone; non-steroidal GRM compounds having afused azadecalin backbone; non-steroidal GRM compounds having aheteroaryl ketone fused azadecalin backbone; and non-steroidal GRMcompounds having an octahydro fused azadecalin backbone. Exemplaryglucocorticoid receptor antagonists having a cyclohexyl-pyrimidinebackbone include those described in U.S. Pat. No. 8,685,973. Exemplaryglucocorticoid receptor antagonists having a fused azadecalin backboneinclude those described in U.S. Pat. Nos. 7,928,237; and 8,461,172.Exemplary glucocorticoid receptor antagonists having a heteroaryl ketonefused azadecalin backbone include those described in U.S. Pat. No.8,859,774. Exemplary glucocorticoid receptor antagonists having anoctohydro fused azadecalin backbone include those described in U.S.Patent Application Publication 20150148341.

“Patient”, “patient in need”, “subject”, “subject in need” and the likerefer to a person having, or suspected of having, a disease or conditionwhich may be treated by administration of a therapeutic drug.

As used herein, the term “Cushing's syndrome” refers to an array ofsymptoms caused by excess cortisol. Cushing's syndrome includesendogenous Cushing's syndrome and ectopic Cushing's syndrome. Suchsymptoms include, for example, elevated blood pressure, elevated bloodglucose, increased weight (typically in the mid-section, and in the facecausing a characteristic “moon-face”), immune suppression, thin skin,acne, depression, hirsutism, and other symptoms.

The terms “Cushing Disease” and “Cushing's Disease” refer topituitary-dependent Cushing's syndrome, e.g., excess cortisol caused bypituitary abnormality (typically a pituitary tumor), e.g., conditions inwhich the pituitary gland releases too much ACTH as a result of a tumorlocated in or near the pituitary gland, or as a result of excess growth(hyperplasia) of the pituitary gland. Cushing Disease is a form ofCushing's syndrome. The term Cushing's syndrome thus includes referenceto Cushing's Disease.

The term “endogenous Cushing's syndrome” refers to a form of Cushing'ssyndrome, where the excess cortisol level is caused by the body's ownoverproduction of cortisol. Patients having endogenous Cushing'ssyndrome include adult patients also having type 2 diabetes; includeadult patients also suffering from glucose intolerance; include adultpatients having hyperglycemia secondary to hypercortisolism; includeadult patients having hyperglycemia secondary to hypercortisolism whohave type 2 diabetes or glucose intolerance; include adult patients whohave failed surgery for Cushing's syndrome; include adult patients whoare not candidates for surgery for Cushing's syndrome; and patientshaving any or all of these symptoms and conditions.

As used herein, a “patient suffering from Cushing's syndrome” refers toany patient suffering from Cushing's syndrome, including endogenousCushing's syndrome; Cushing's Disease; or a condition associated withCushing's syndrome. A condition associated with Cushing's syndrome maybe, without limitation, a condition associated with endogenous Cushing'ssyndrome; hyperglycemia secondary to hypercortisolism; a condition ofhypercortisolism in an endogenous Cushing's syndrome patient, saidpatient having type 2 diabetes mellitus or glucose intolerance; acondition of hyperglycemia secondary to hypercortisolism in anendogenous Cushing's syndrome patient, said patient having type 2diabetes mellitus or glucose intolerance and having failed surgery;hyperglycemia secondary to hypercortisolism in an endogenous Cushing'ssyndrome patient, said patient having type 2 diabetes mellitus orglucose intolerance and having failed surgery or who is not a candidatefor surgery; and other conditions associated with Cushing's syndrome.

Treating Cushing's syndrome, including endogenous Cushing's syndrome andCushing's disease, may include administration of a glucocorticoidreceptor modulator (GRM), such as, e.g., mifepristone. TreatingCushing's syndrome, including endogenous Cushing's syndrome, may includecontrolling hyperglycemia secondary to hypercortisolism. TreatingCushing's syndrome, including endogenous Cushing's syndrome, may includecontrolling hyperglycemia secondary to hypercortisolism in an adult withpatient type 2 diabetes or glucose intolerance and suffering fromendogenous Cushing's syndrome, who has failed surgery for Cushing'ssyndrome, or is not a candidate for surgery for Cushing's syndrome.

As used herein, the terms “monitor”, “to monitor”, “monitoring” and thelike refer to a physician or other person paying attention to, keepingtrack of, following the measurements of or course of, one or more ofanalyte measurements (e.g., potassium levels, cortisol levels, ACTHlevels, or other measurements), patient symptoms, patient response totreatment, and other clinical signs related to a disease or disorder,the symptoms of a disease or disorder, the course of a disease ordisorder, and the course of treatment of a disease or disorder.Monitoring may include scheduling an appointment for a patient to see aphysician or other practitioner, or to have a test (e.g., a blood,urine, or saliva test) performed, as well as inspecting or evaluatingthe results of such an appointment or test.

As used herein, the term “Adrenocorticotrophic Hormone” (ACTH) refers tothe peptide hormone produced by the anterior pituitary gland. ACTHstimulates secretion of cortisol and other glucocorticoids (GCs) byspecialized cells of the adrenal cortex, which help cells synthesizeglucose, catabolize proteins, mobilize free fatty acids and inhibitinflammation in allergic responses. In healthy mammals, ACTH secretionis tightly regulated. ACTH secretion is positively regulated bycorticotropin releasing hormone (CRH), which is released by thehypothalamus. ACTH secretion is negatively regulated by cortisol andother glucocorticoids.

The term “Adrenocorticotropic hormone (ACTH)-dependent Cushing'ssyndrome” refers to a form of endogenous Cushing's syndrome, which iscaused by abnormal production of ACTH. There are two major forms ofACTH-dependent Cushing's syndrome: Cushing Disease (accounting for about80% of the cases) and ectopic ACTH syndrome (accounting for 20% of thecases).

“Treat”, “treating” and “treatment” refer to any indicia of success inthe treatment or amelioration of a pathology or condition, including anyobjective or subjective parameter such as abatement; remission;diminishing of symptoms or making the pathology or condition moretolerable to the patient; slowing in the rate of degeneration ordecline; making the final point of degeneration less debilitating; orimproving a patient's physical or mental well-being. The treatment oramelioration of symptoms can be based on objective or subjectiveparameters; including the results of a physical examination;histopathological examination (e.g., analysis of biopsied tissue);laboratory analysis of urine, saliva, tissue samples, serum, plasma, orblood; or imaging.

As used herein, “treating a patient who is suffering from Cushing'ssyndrome”, or treating a subject who is suffering from Cushing'ssyndrome”, or similar phrases refer to, without limitation, treating apatient suffering from Cushing's syndrome, including endogenousCushing's syndrome; treating a patient suffering from Cushing's Disease;or treating a patient suffering from a condition associated withCushing's syndrome. A condition associated with Cushing's syndrome isdiscussed above. For example, treating a patient who is suffering fromCushing's syndrome may include administering mifepristone or other GRMto control hyperglycemia secondary to hypercortisolism in adult patientswith endogenous Cushing's syndrome who have type 2 diabetes mellitus orglucose intolerance and have failed surgery or are not candidates forsurgery.

As used herein, the terms “administer,” “administering,” “administered,”“administration,” and the like, refer to providing a compound or acomposition (e.g., one described herein), to a subject or patient. Thus,for example, “administration to a patient” refers to the delivery of adrug or other therapeutic into the body of a patient in need oftreatment by the drug or therapeutic, effective to achieve a therapeuticeffect. Administration may be by any suitable route of administration,including, for example, oral administration; intravenous administration;subcutaneous administration; parenteral administration; intra-arterialadministration; nasal administration; topical administration; and otherroutes of administration.

The term “administering” includes oral administration, topical contact,administration as a suppository, intravenous, intraperitoneal,intramuscular, intralesional, intrathecal, intranasal, or subcutaneousadministration, or the implantation of a slow-release device, e.g., amini-osmotic pump, to a subject. Administration is by any route,including parenteral and transmucosal (e.g., buccal, sublingual,palatal, gingival, nasal, vaginal, rectal, or transdermal). Parenteraladministration includes, e.g., intravenous, intramuscular,intra-arteriole, intradermal, epicutaneous, subcutaneous,intraperitoneal, intraventricular, and intracranial. Other modes ofdelivery include, but are not limited to, the use of liposomalformulations, intravenous infusion, and transdermal patches.

The term “sample” refers to a biological sample obtained from a humansubject. The sample can be any cell, tissue or fluid from a humansubject, for example, a sample of blood (including whole blood or anyfraction of thereof, e.g., plasma or serum), saliva, urine, tear, sweat,and the like. Samples can be subject to various treatment, storage orprocessing procedures before being analyzed according to the methodsdescribed herein. Generally, the terms “sample” or “samples” are notintended to be limited by their source, origin, manner of procurement,treatment, processing, storage or analysis, or any modification.

The term “morning serum sample” refers to a serum sample obtained from ahuman subject in the morning, where morning may be a time between about6 AM to about 10 AM, or between about 7 AM and about 9 AM, or other timeunderstood as during the morning.

The term “morning serum cortisol sample” refers to a morning serumsample in which the level, e.g., the concentration, of cortisol ismeasured.

The term “morning serum ACTH sample” refers to a morning serum sample inwhich the level, e.g., the concentration, of ACTH is measured.

As used herein, the term “AUC” means the area under the plasma or serumconcentration-time curve, and serves as a measure of the plasma levelsof a drug in a subject to whom the drug has been administered.

As used herein, the term “C_(max)” means the maximum observed plasma orserum concentration of a drug in a subject to whom the drug has beenadministered.

The term “measuring the level,” in the context of cortisol, ACTH,mifepristone, or other compounds, refers to determining, detecting, orquantitating the amount, level, or concentration of, for example,cortisol, ACTH, mifepristone, or other compound in a sample obtainedfrom a subject. Plasma or serum samples are often used for measuringACTH or cortisol level. In preferred embodiments of this invention, aserum or plasma sample taken from a patient in the morning (e.g.,between about 6 AM to about 10 AM, for example, at about 6, 7, 8, or 9AM) is used for measuring the level of ACTH by a radioimmunoassay (RIA),most preferable a two-site RIA, such as performed by Quest Diagnostics(Secaucus, N.J. 07094). In other preferred embodiments, a serum orplasma sample taken from a patient in the morning (e.g., between about 6AM to about 10 AM, for example, at about 6, 7, 8, or 9 AM) is used formeasuring the level of cortisol by high-performance liquidchromatography/triple quadrupole-mass spectrometry (LC-MS/MS), such asperformed by Quest Diagnostics (Secaucus, N.J. 07094).

The term “elevated level”, “elevated amount”, or “elevatedconcentration” refers to the level or amount of the analyte that ishigher than the normal reference value for that analyte.

As used herein, the term “effective amount” or “therapeutic amount”refers to an amount of a pharmacological agent effective to treat,eliminate, or mitigate at least one symptom of the disease beingtreated. In some cases, “therapeutically effective amount” or “effectiveamount” can refer to an amount of a functional agent or of apharmaceutical composition useful for exhibiting a detectabletherapeutic or inhibitory effect. The effect can be detected by anyassay method known in the art. The effective amount can be an amounteffective to reduce cortisol binding to GR, or to reduce cortisolactivation of GR, in a patient.

As used herein, the term “compound” is used to denote a molecular moietyof unique, identifiable chemical structure. A molecular moiety(“compound”) may exist in a free species form, in which it is notassociated with other molecules. A compound may also exist as part of alarger aggregate, in which it is associated with other molecule(s), butnevertheless retains its chemical identity. A solvate, in which themolecular moiety of defined chemical structure (“compound”) isassociated with a molecule(s) of a solvent, is an example of such anassociated form. A hydrate is a solvate in which the associated solventis water. The recitation of a “compound” refers to the molecular moietyitself (of the recited structure), regardless of whether it exists in afree form or an associated form.

Potassium levels in blood of normal adult humans typically range fromabout 3.5 milliEquivalents per Liter (mEq/L) to about 5.5 or 6 mEq/L.Levels outside this range can lead to serious clinical abnormalities,including, for example, changes in blood pressure, heart rate, muscleand nerve activity, kidney and fluid problems, and other clinicalabnormalities. Plasma or serum samples are often used for measuringpotassium level in a patient's blood.

Hypokalemia is the condition of low potassium levels in the blood. Asnoted above, normal levels of potassium are between about 3.5 mEq/L andabout 5.3 mEq/L. Potassium levels below about 3.5 mEq/L are typicallyconsidered to be low, and to indicate hypokalemia, and to requireobservation and medical care; levels below about 2.5 mEq/L areconsidered severe hypokalemia, and may require immediate clinicalattention. Such low potassium levels (below about 3.5 mEq/L) can beserious, leading to, for example, neuromuscular disorders includingcramps, paresthesia, paralysis, and other disorders; renal and urinarydisorders; cardiovascular disorders including hypertension, heartpalpitations, irregular heart rate; and other clinical abnormalities.Hypokalemia can lead to increased risk of sudden cardiac arrest. Thus,hypokalemia is a serious condition, and can be life-threatening.Treatment for hypokalemia may include oral or intravenous potassium(e.g., a potassium salt such as KCl); administration of apotassium-sparing diuretic such as, e.g., triamterene, amiloride, orother such drug; administration of a mineralocorticoid receptorantagonist such as spironolactone, eplerenone, or other such drug;administration of a steroid synthesis inhibitor such as, e.g.,ketoconazole or itraconazole; or other treatment.

Somatostatin and somatostatin analogs (e.g., octreotide, pasireotide,and lanreotide) may be used to treat hypokalemia. Somatostatin andsomatostatin analogs are believed to act to treat hypokalemia, at leastin part, by reducing ACTH levels, thus leading to reduced cortisollevels, and so to reduced mineralocorticoid activation.

Steroid synthesis inhibitor include, for example, ketoconazole,itraconazole, fluconazole, metyrapone, etomidate, and other drugs, andmay be used to treat hypokalemia. Steroid synthesis inhibitors arebelieved to act, at least in part, by reducing cortisol synthesis, thusleading to reduced cortisol levels, and so to reduced mineralocorticoidactivation.

Potassium-sparing diuretics such as, e.g., amiloride (MIDAMOR®) andtriamterene (e.g., DYRENIUM®) may be used to treat hypokalemia.

Mineralocorticoid receptor antagonists (also termed mineralocorticoidantagonists, or antimineralocorticoids) reduce or block the activationof MR. Mineralocorticoid antagonists include, for example,spironolactone (e.g., ALDACTONE®), eplenerone (INSPRA®), canrenone, andfineronone. Mineralocorticoid antagonists may be administered to treathypokalemia. For example, spironolactone (e.g., from about 50 mg per dayup to about 300 mg per day) may be administered to control hypokalemia.

One method of treating hypokalemia includes potassium replacementtherapy (potassium supplementation) by oral administration of potassium(typically 40-120 mEq per day, although in some cases about 10 mEq/dayup to about 340 mEQ/day may be administered). Alternatively, or inaddition, potassium replacement therapy (potassium supplementation) maybe performed by intravenous administration of potassium.

As used herein, the term “composition” is intended to encompass aproduct comprising the specified ingredients such as the said compounds,their tautomeric forms, their derivatives, their analogues, theirstereoisomers, their polymorphs, their deuterated species, theirpharmaceutically acceptable salts, esters, ethers, metabolites, mixturesof isomers, their pharmaceutically acceptable solvates andpharmaceutically acceptable compositions in specified amounts, as wellas any product which results, directly or indirectly, from combinationof the specified ingredients in the specified amounts. Such term inrelation to a pharmaceutical composition is intended to encompass aproduct comprising the active ingredient (s), and the inert ingredient(s) that make up the carrier, as well as any product which results,directly or indirectly, in combination, complexation or aggregation ofany two or more of the ingredients, or from dissociation of one or moreof the ingredients, or from other types of reactions or interactions ofone or more of the ingredients. Accordingly, the pharmaceuticalcompositions of the present invention are meant to encompass anycomposition made by admixing compounds of the present invention andtheir pharmaceutically acceptable carriers.

In some embodiments, the term “consisting essentially of” refers to acomposition in a formulation whose only active ingredient is theindicated active ingredient, however, other compounds may be includedwhich are for stabilizing, preserving, etc. the formulation, but are notinvolved directly in the therapeutic effect of the indicated activeingredient. In some embodiments, the term “consisting essentially of”can refer to compositions which contain the active ingredient andcomponents which facilitate the release of the active ingredient. Forexample, the composition can contain one or more components that provideextended release of the active ingredient over time to the subject. Insome embodiments, the term “consisting” refers to a composition, whichcontains the active ingredient and a pharmaceutically acceptable carrieror excipient.

“Pharmaceutically-acceptable excipient” and “pharmaceutically-acceptablecarrier” refer to a substance that aids the administration of an activeagent to—and absorption by—a subject and can be included in thecompositions of the present invention without causing a significantadverse toxicological effect on the patient. Non-limiting examples ofpharmaceutically-acceptable excipients include water, NaCl, normalsaline solutions, lactated Ringer's, normal sucrose, normal glucose,binders, fillers, disintegrants, lubricants, coatings, sweeteners,flavors and colors, and the like. As used herein, the term“pharmaceutically acceptable carrier” is intended to include any and allsolvents, dispersion media, coatings, antibacterial and antifungalagents, isotonic and absorption delaying agents, and the like,compatible with pharmaceutical administration. The use of such media andagents for pharmaceutically active substances is well known in the art.Except insofar as any conventional media or agent is incompatible withthe active compound, use thereof in the compositions is contemplated.Supplementary active compounds can also be incorporated into thecompositions. One of ordinary skill in the art will recognize that otherpharmaceutical excipients are useful in the present invention.

The term “normal level” refers to the average level of an analyte asdetermined by measurements of samples obtained from multiple normalsubjects.

The term “normal cortisol level” refers to the average level of cortisolas determined by measurements of samples (e.g., serum samples) obtainedfrom multiple normal subjects.

The term “normal level” refers to the average level of ACTH asdetermined by measurements of samples (e.g., serum samples) obtainedfrom multiple normal subjects.

“Standard control” as used herein refers to a sample comprising apredetermined amount of an analyte (such as ACTH or cortisol) suitablefor the use of an application of the present invention, in order toserve as a comparison basis for providing an indication of the relativeamount of the analyte (e.g., ACTH or cortisol) that is present in a testsample. A sample serving as a standard control provides an averageamount of an analyte such as ACTH or cortisol that is representative fora defined sample type (e.g., plasma, serum, saliva, or urine) taken at adefined time of the day (e.g., 8 AM) from an average individual who isnot suffering from or at increased risk of later developing hypokalemiaor any associated disorder or complication and has been given the sameGRM treatment. As used herein, a “blood sample” may be a whole bloodsample, serum sample, plasma sample, or blood cell sample as appropriatefor measuring an analyte level by art-known methods according toconventional use. Similarly, “blood level” of a particular analyte maybethe level of the analyte in the whole blood, serum, plasma, or bloodcells. For example, the blood level of potassium, ACTH, or cortisolmaybe the level of each analyte in a serum or plasma sample taken from asubject being tested.

The term “average,” as used in the context of describing an individual(especially a human subject) who does not have and is not at increasedrisk of developing hypokalemia or any related condition or disorderprior to receiving GRM treatment, refers to certain characteristics,such as the level or amount of an analyte (such as ACTH or cortisol)present in a sample taken from the individual without receiving GRMtreatment, that are representative of the average amount or level of theanalyte found in a randomly selected group of individual subjects whohave not been diagnosed with and are not susceptible to hypokalemia orany related diseases or conditions and therefore can serve as an“average normal value” or “standard control value” for the particularanalyte prior to GRM treatment. This selected group should comprise asufficient number of individuals (e.g., at least 200 or 500 or more)such that the average value (i.e., level or amount) of the analyte ofinterest (e.g., ACTH or cortisol) assessed among these individualsreflects, with reasonable accuracy, the corresponding level or amount ofthe analyite found in the general population of non-hypokalemicindividuals with no known risk for the disorder or related conditionsupon receiving GRM treatment. In some cases, the selected group ofindividuals generally have the same gender, are similar in age (e.g.,within a 5- or 10-year age difference from one another), have similarethnic and medical backgrounds. Depending on the analyate, the averagevalue or standard control value may need to be ascertained from samplestaken from these individuals at about the same time during the day(e.g., 6 AM, 8 AM, 12 PM, 4 PM, or 6 PM). The average or standardcontrol value of any particular analyte may also vary depending on thespecific assay or assay format (including the specific reagents)utilized for quantitatively measuring the analyte, and therefore can bemade available either by way of experimentation or by way of assaymanufacturer's information.

The term “about” when used in reference to a pre-determined valuedenotes a range encompassing ±10% of the pre-determined value.

The term “steady state of plasma or serum GRM concentration” or thelike, as used herein, describes a state in which the GRM level in theplasma or serum does not significantly increase (e.g., no more thanabout 10%, 15%, 20%, 25%, or 30% increase) with subsequent doses of GRMadministration in a Cushing's syndrome patient who has been receiving adaily (or other regular frequency of administration) dose of a GRM (suchas mifepristone) over a period of several days (e.g., at least about 3,4, or 5 days, at least about 5 to about 10 days, or about 7 to about 21days, such as about 14 days).

C. Hypokalemia Risk

The methods disclosed herein are applicable for identifying patients athigh risk for developing hypokalemia before potassium levels in thosepatients drop below safe levels. Normal potassium levels are typicallybetween about 3.5 mEq/L and about 5.3 mEq/L. Levels of potassium below3.5 mEq/L are considered hypokalemic, and levels below about 2.5 mEq/Lare severely hypokalemic. Hypokalemia can cause life-threatening cardiacproblems including long QT syndrome, cardiac arrhythmias, and can leadto sudden death. Identifying patients who may become hypokalemic beforetheir potassium levels drop below 3.5 mEq/L could avoid seriouscomplications in those patients, since the effects of low potassium areimmediate, and the condition can become life-threatening very quickly.Applicant discloses herein methods for identifying, and for providingprophylactic treatment to, patients at high risk for developinghypokalemia before potassium levels in those patients drop below safelevels, effective to prevent the development of, or reduce the severityof, hypokalemia in those patients.

Cushing's syndrome patients receiving GRM treatment, such asmifepristone treatment, are be at risk of developing hypokalemia.Identification of Cushing's syndrome patients who may on a course todevelop hypokalemia before the potassium levels drop below normal, orbefore other symptoms arise, allows prophylactic treatment that canavoid the development of hypokalemia, rather than merely attempt toalleviate it after it has become evident.

Applicant has discovered that measurement of ACTH levels, cortisollevels, or both, of Cushing's syndrome patients receiving GRM treatment,such as mifepristone treatment, allows identification of those patientswho would otherwise go on to suffer from hypokalemia, by determining,e.g., one or both of the following: cortisol levels above about 700nmol/L (e.g., at or above 750 nmol/L) following a period of time (e.g.,two weeks) after initiation of treatment with a GRM such asmifepristone; and ACTH levels above about 100 pg/mL (e.g., at or above112 pg/mL) following a period of time (e.g., two weeks) after initiationof treatment with a GRM such as mifepristone.

The types of samples that are suitable for ACTH determination can beserum, plasma, saliva, urine, or any other biological fluid taken from asubject. In preferred embodiments, the sample is a serum sample, or is aplasma sample. The level of ACTH can be measured using various methods,including but not limited to, immunoassays, e.g., competitiveimmunoassay, radioimmunoassay (MA), immunofluorometric enzyme assay, andELISA; competitive protein-binding assays; liquid chromatography (e.g.,HPLC); and mass spectrometry, e.g., high-performance liquidchromatography/triple quadrupole-mass spectrometry (LC-MS/MS).Commercial kits for measuring ACTH are readily available, e.g., fromMayo clinic (Test ID: ACTH), Siemens Healthcare Global (Immulite® 2000ACTH assay), and Roche Molecular Diagnostics (Catalog No. 03255751190).In preferred embodiments, ACTH levels are measured using aradioimmunoassay (RIA), most preferable a two-site MA, such as performedby Quest Diagnostics (Secaucus, N.J. 07094).

The types of samples that are suitable for cortisol determination can beserum, plasma, saliva, urine, or any other biological fluid taken from asubject. In preferred embodiments, the sample is a serum sample, or is aplasma sample. The level of cortisol can be measured using variousmethods, including but not limited to, immunoassays, e.g., competitiveimmunoassay, radioimmunoassay (MA), immunofluorometric enzyme assay, andELISA; competitive protein-binding assays; liquid chromatography (e.g.,HPLC); and mass spectrometry, e.g., high-performance liquidchromatography/triple quadrupole-mass spectrometry (LC-MS/MS). Inpreferred embodiments, cortisol levels are measured using LC-MS/MS, suchas performed by Quest Diagnostics (Secaucus, N.J. 07094).

D. Glucocorticoid Receptor Modulators (GRM)

Generally, treatment of Cushing's syndrome, such as ACTH-dependentCushing's syndrome, can be provided by administering an effective amountof a glucocorticoid receptor modulator (GRM) of any chemical structureor mechanism of action. In embodiments, the GRM is mifepristone. Inembodiments, the GRM is a selective GRM (SGRM). In embodiments,prevention of hypokalemia in Cushing's syndrome patients, or reducingthe risk of hypokalemia in Cushing's syndrome patients, or identifyingCushing's syndrome patients at particular risk of developinghypokalemia, where such patients are receiving treatment comprisingadministration of a GRM, such as mifepristone, can be provided byadministering a treatment for hypokalemia before hypokalemia is observedin the patient when ACTH, or cortisol, or both, are determined to riseexcessively following increase in the GRM dosage administered to theCushing's syndrome patient. In preferred embodiments, the GRM ismifepristone. Provided herein are further classes of exemplary GRMs,including exemplary nonsteroidal SGRMs, and specific members of suchclasses. However, one of skill in the art will readily recognize otherrelated or unrelated GRMs and SGRMs that can be employed in thetreatment methods described herein.

E. Treatment for Hypokalemia

Agents suitable for use in treating hypokalemia in combination with theGRM as disclosed herein include potassium supplements; potassium-sparingdiuretics; mineralocorticoid receptor antagonists; steroid synthesisinhibitors (e.g., ketoconazole, itraconazole, and others); and otheragents that either raise potassium or reduce cortisol levels (e.g.,mitotane). Thus, treatment for hypokalemia, including prophylactictreatment for hypokalemia (that is, prior to the patient's potassiumlevels dropping below 3.5 mEq/L) includes, without limitation,administration of one or more of potassium supplements;potassium-sparing diuretics; mineralcorticoid receptor antagonists;steroid synthesis inhibitors; and other agents that either raisepotassium or reduce cortisol levels. Typically, treatment forhypokalemia is prophylactic treatment when administered to a subjectwhose potassium levels are not below the lower limit for normalpotassium (i.e., not below 3.5 mEq/L). However, in embodiments,hypokalemia treatments may be considered prophylactic treatment forhypokalemia when administered to patients with potassium levelsminimally below about 3.5 mEq/L (e.g., at about 3.4, or 3.3 mEq/L).

In still further embodiments, more than one agent for treatinghypokalemia may be administered simultaneously, or sequentially in anyorder during the entire or portions of the treatment period. The twoagents may be administered following the same or different dosingregimens.

The present methods can be combined with other means of Cushing'ssyndrome treatment such as surgery, radiation, targeted therapy,immunotherapy, or other methods.

In embodiments, determination that the cortisol level in a patient'sblood (e.g., the morning serum cortisol level) is above about 700 nmol/L(e.g., at or above 750 nmol/L) identifies that patient as one at risk ofhypokalemia, and indicates that prophylactic hypokalemia treatmentshould be initiated.

In embodiments, determination that the ACTH level in a patient's blood(e.g., the morning serum ACTH level) is above about 100 pg/mL (e.g., ator above 112 pg/mL) identifies that patient as one at risk ofhypokalemia, and indicates that prophylactic hypokalemia treatmentshould be initiated.

The GRM or SGRM therapy disclosed herein can reduce the risk ofhypokalemia, and may prevent development of hypokalemia, and thus conferbeneficial clinical outcome to Cushing's syndrome patients. The clinicalbenefits of preventive and prophylactic treatment of hypokalemia includereducing risk of fatigue, edema, and hypertension in the patient;avoiding or reducing the risk of muscle weakness, cramps, and musclespasms; avoiding or reducing the risk of neurological problems such asparesthesia and paralysis; avoiding or reducing the risk of renalproblems such as polyuria, polydipsia, and nocturia; avoiding orreducing the risk of gastrointestinal disorders such as abdominalcramps, constipation, nausea, and vomiting; avoiding or reducing therisk of long Q-T syndrome; avoiding or reducing the risk of cardiacpalpitations and arrhythmias; avoiding or reducing risk of suddencardiac arrest; and other benefits.

Although the foregoing invention has been described in some detail byway of illustration and example for purposes of clarity ofunderstanding, it will be readily apparent to those of ordinary skill inthe art in light of the teachings of this invention that certain changesand modifications may be made thereto without departing from the spiritor scope of the appended claims.

All patents, patent applications, patent publications, and otherreferences cited herein, both supra and infra, are hereby incorporatedby reference herein.

EXAMPLES

The following examples are presented by way of illustration ofembodiments of the methods disclosed herein, and serve to illustrate,but not to limit, the present disclosure of methods of treating patientssuffering from Cushing's syndrome, including Cushing's Disease.

Example 1 High Serum Cortisol Levels Prior to MifepristoneAdministration and High Serum ACTH Levels Following Two Weeks ofMifepristone Treatment Predict Hypokalemia

All events of severe/recurrent hypokalemia were preceded by declining ofpotassium levels: 3 of 4 patients had previous low potassium values andone patient had previously normal potassium levels that were decliningprior to the development of the event.

FIG. 1 shows the association between ACTH levels and potassium (3.5mmol/L, ≥3.5 mmol/L). It shows that patients with potassium levels <3.5mmol/L had on average higher ACTH levels on the same study day.

FIG. 2 demonstrates the association between levels of potassium (<3.5mEq/L, ≥3.5 mEq/L) and Total Cortisol levels. It shows that patientswith potassium levels <3.5 mEq/L had on average higher Total Cortisollevels on the same study day.

Hypokalemia with Dose Initiation of 300 mg/Day (Early-Onset Hypokalemia)

The risk of experiencing at least one episode of hypokalemia (potassiumlevel <3.5 mEq/L) after 7 to 14 Days of exposure to KORLYM(mifepristone) was evaluated using stepwise multivariable logisticregression and single-variable logistic regression models. The followingindependent factors were evaluated for potential association withhypokalemia based on the biology of the disease: total cortisol at Day1, ACTH at Day 1, and potassium level at Day 1.

The hypothesis that higher total cortisol levels at Day 1 are associatedwith post-baseline hypokalemia was supported by examining a variety ofcriteria for model fit across the models, including residuals, AIC(Akaike Information Criteria), BIC (Schwarz Bayesian InformationCriterion), and associated ROC (Receiver Operating Characteristics)curves.

Results of the single-variable logistic regression with ACTH at Day 14as an independent variable are presented below in Table 1.

TABLE 1 Maximum Likelihood Estimates of Logistic Regression Coefficientsfor the Odds of Early Hypokalemia Standard 95% CI 95% CI Estimate ErrorLower Limit Upper Limit p-value Intercept −4.7856 1.5239 −7.7723 −1.79890.0017 cort_01 0.00511 0.00211 0.000972 0.00926 0.0155

To determine the day-1 serum cortisol (cort_01) cut-off value that bestdifferentiates patients at higher vs. lower risk for early hypokalemia,we considered both the points on the ROC curve which would balancesensitivity and specificity. If the ROC curve fitted to the observeddata were exactly equal to the true ROC curve, then a value of 750nmol/L at the Day 1 visit (see FIG. 3) would provide a good balancebetween sensitivity and specificity.

The estimated probabilities of developing early hypokalemia andassociated sensitivity and specificity estimates were fitted to theobserved data.

Table 2 summarizes the number of patients who experienced at least oneepisode of early hypokalemia by (Day 1 visit Total Cortisol (cort_01)level).

The performance of the identified cut-off using total serum cortisollevel of 750 nmol/L results in a 6.8-fold increase in risk for patientswith total serum cortisol >750 nmol/L level before KORLYM dosingcompared with patients with total serum cortisol level ≤750 nmol/Lbefore KORLYM administration (58.3% vs. 8.6%, Fisher's Exact p-value<0.0011). That is, seven (58.3%) of 12 patients with cort_01 values ≥750nmol/L developed early hypokalemia, (i.e., by the Day 7 or Day 14visit), whereas 3 (8.6%) of 35 patients with cort_01 values <750 nmol/Ldeveloped early hypokalemia (Fisher's Exact test p-value=0.0011). Thiscorresponds to a sensitivity of 70.0% and a specificity of 86.5%.

TABLE 2 Patients with Early Hypokalemia (at Day 7 or Day 14 visit), byTotal Serum Cortisol Level at Day 1 No Early Early HypokalemiaHypokalemia Total n (%) (n = 37) (n = 10) (n = 47) Total cortisol, <750nmol/L 32 (86.5) 3 (30.0) 35 (74.5) Total cortisol, ≥750 nmol/L  5(13.5) 7 (70.0) 12 (25.5) Hypokalemia, K < 3.5 mmol/L.Hypokalemia with Dose Escalation Above 300 mg/Day (Late-OnsetHypokalemia)

The risk of experiencing at least one episode of hypokalemia (potassiumlevel <3.5 mmol/L) after 28 Days of exposure to KORLYM was evaluatedusing stepwise multivariable logistic regression and single-variablelogistic regression models. The following independent factors wereevaluated for potential association with hypokalemia based on thebiology of the disease: total cortisol at Day 1 and Day 14 (cort_01 andcort_14), ACTH at Day 1 and Day 14 (ACTH_01 and ACTH_14), and potassiumlevels at Day 1 and Day 14 (K_01 and K_14).

ACTH levels at the Day 14 Visit are associated with the risk ofdeveloping subsequent hypokalemia during treatment with KORLYM at dosesgreater than 300 mg. This was supported by examining a variety ofcriteria for model fit across the models, including residuals, AIC(Akaike Information Criteria), BIC (Schwarz Bayesian InformationCriterion), and associated ROC (Receiver Operating Characteristics)curves.

The single-variable logistic regression with ACTH at Day 14 as anindependent variable shows a statistically significant associationbetween the odds of developing late-onset hypokalemia and ACTH levels atDay 14 (p=0.0032. Results of the single-variable logistic regressionwith ACTH at Day 14 as an independent variable are presented below inTable 3, and the probabilities and odds of developing hypokalemia arepresented below in Table 4.

TABLE 3 Maximum Likelihood Estimates of Logistic Regression Coefficientsfor the Odds of Hypokalemia 95% CI Standard 95% CI Upper Estimate ErrorLower Limit Limit p-value Intercept −2.8357 0.8147 −4.4325 −1.23890.0005 ACTH_14 0.0210 0.00713 0.00703 0.0350 0.0032

Using the above estimates, we note, for example, that the odds ofdeveloping hypokalemia increase more than 4-fold when ACTH levelincrease from 48 pg/mL (1^(st) Quartile at Day 14) to 123 pg/mL (3^(rd)quartile at Day 14):

TABLE 4 Increase in the Odds of Developing Hypokalemia Probability ofDeveloping Odds of Developing Hypokalemia, % Hypokalemia, % ACTH = 48mmol/L 13.9 16.1 ACTH = 123 mmol/L 43.7 77.6where the odds are calculated by dividing (the probability of gettinghypokalemia) by (the probability of not getting hypokalemia). ForACTH=48 mmol/L, the probability of getting hypokalemia is 13.9%; so theprobability of not getting hypokalemia is 100%-13.9%=86.1%; the odds ofgetting hypokalemia with an ACTH of 48 mmol/L is then13.9/(100-13.9)=16.1%. A similar calculation for ACTH=123 mmol/L showsthat the odds of getting hypokalemia with an ACTH level of 123 mmol/Lare 43.7/(100-43.7)=77.6%. The ratio of the odds for getting hypokalemiawith an ACTH level of 123 mmol/L as compared to the odds for gettinghypokalemia with an ACTH level of 48 mmol/L are then 77.6% divided by16.1%=4.82. That is, the odds that a patient with an ACTH level of 123mmol/L will suffer from hypokalemia are more than 4 times greater thanthe odds that a patient with an ACTH level of 48 mmol/L will suffer fromhypokalemia.

To determine the ACTH cut-off value that best differentiates patients athigher risk from those at lower risk, we considered the points on theROC curve that would balance sensitivity and specificity. Fitting theROC curve to the observed data via a logistic regression model resultsin an ACTH value of 112 pg/mL at the Day 14 visit that provides a goodbalance between sensitivity and specificity. The ACTH_14 cut-off valueof 112 pg/mL provides a high level of sensitivity of the ACTH-based testfor predicting future hypokalemia, together with a low false-positiverate.

The maximum likelihood estimates for developing hypokalemia andassociated specificity estimates based on the model fitted to theobserved data are presented in Tables 3 and 4 above as well as in FIGS.3 and 4.

A sensitivity analysis using an ACTH cutoff of 112 pg/mL correspondingto a point on the ROC curve with an optimal balance of specificity andsensitivity results in a 6-fold (80% vs. 13.3%, Fisher's Exact p-value<0.0001) increase in risk for patients with ACTH levels above 112 pg/mLcompared to patients with ACTH levels below 112 pg/mL.

Table 5 summarizes the number of patients who experience at least oneepisode of subsequent (post Day 28) hypokalemia by ACTH level duringfirst 2 weeks. The performance of the identified cut-off using an ACTHlevel of 112 pg/mL corresponding to a point on the ROC curve with anoptimal balance of specificity and sensitivity results in a 5.64-foldincrease in risk for patients with ACTH>112 pg/mL at Day 14 comparedwith patients with ACTH≤112 pg/mL at Day 14 (75.0% vs. 13.3%, Fisher'sExact p-value <0.0001) (Table 2). This corresponds to a sensitivity of75.0% and a specificity of 86.7%.

TABLE 5 Patients with Subsequent Hypokalemia, by ACTH after 2 Weeks ofTreatment with KORLYM No Hypokalemia, Hypokalemia^(a) Total (n = 30) n =16 (n = 46) ACTH <112 pg/mL, n (%) 26 (86.7)  4 (25.0) 30 (65.2) ACTH≥112 pg/mL,  4 (13.3) 12 (75.0) 16 (21.7) n (%) ^(a)Potassium, <3.5mmol/L.Factors Associated with Severe/Recurrent Hypokalemia with DoseEscalation >300 mg/Day

Patients were defined to have severe/recurrent hypokalemia for thisanalysis if they had at least one value of potassium of 2.5 mmol/L orlower, or if they had recurrent hypokalemia (hypokalemia occurringduring multiple visits after Day 14 visit). Nine (19.1%) of 47 patientsexperienced severe/recurrent hypokalemia, with two who had at least onepotassium value of 2.5 mmol/L or lower, and all 9 had recurrenthypokalemia prior to or at the Week 24/Early termination visit.

To incorporate the above definition of severe/recurrent hypokalemia intothe analysis, an ordinal hypokalemia response variable was defined asfollows (over the previously defined time frame from the Day 14 visit tothe Week 24/Early termination visit, inclusive):

-   -   2: Severe/recurrent Hypokalemia    -   1: Hypokalemia (Non-Severe)    -   0: No Hypokalemia

A Cochran-Mantel-Haenszel (CHM) test using an alternative hypothesis of“Row Mean Scores Differ” resulted in a corresponding p-value of 0.0017.It indicated that the Day 14 ACTH cutoff value of 112 pg/mL appears tobe a useful threshold for distinguishing patients at higher risk fordeveloping hypokalemia or severe/recurrent hypokalemia. Of 15 patientswith high Day 14 visit ACTH values (>112 pg/mL) by Day 14, 5 (33.3%)developed subsequent hypokalemia at Day 28 or later, and 7 (46.7%)developed subsequent severe/recurrent hypokalemia (Table 6). Of the 30patients with low ACTH values by Day 14, 2 (6.7%) of developedhypokalemia, and 2 (6.7%) developed severe/recurrent hypokalemia on orafter Day 28 (CMH test p-value=0.0017).

TABLE 6 Number of Patients with Subsequent Hypokalemia orSevere/recurrent Hypokalemia within First 28 Days of Treatment withKORLYM, by Day 14 visit ACTH of 112 pg/mL No Non-Severe Severe/Recurrentn (%) Hypokalemia Hypokalemia Hypokalemia Total ACTH 26 2 2 30 (67.7)<112 pg/mL ACTH  3 5 7 15 (33.3) ≥112 pg/mL Total 29 (64.4) 7 (15.6) 9(20.0) 45 (100)

Effect of Potassium Supplements and Potassium-Sparring Agents

ACTH is a predictor of hypokalemia in patients regardless of treatmentwith anti-hypokalemic drugs.

The risk of developing hypokalemia after Day 14 was higher in patientswith higher ACTH regardless whether they were treated prior to dosingwith potassium supplements. Out of 14 patients who had been receivingtreatment for hypokalemia before dosing with KORLYM, 6 (42.9%) developedhypokalemia after dosing with KORLYM. Of those, 5 (80%) patients had anACTH>112 pg/mL on Day 14. The other 8 patients who had been receivingtreatment for hypokalemia before dosing did not develop hypokalemiaafter dosing. Seven (87.5%) of these patients had ACTH level on Day14≤112 pg/mL.

Patients at high risk should be treated with a sufficient dosage ofpotassium-sparing medications.

These conclusions hold regardless of whether patients were treated forhypokalemia with potassium supplements at baseline or at any pointduring the study.

Example 2 High Serum ACTH Levels Predict Hypokalemia

Clinical experience based on previous clinical studies of mifepristoneadministered to healthy volunteers identified headache, gastrointestinalsymptoms including diarrhea, nausea and vomiting, and rash as frequentlyreported adverse events. Hypokalemia and rash appear to be more commonin subjects receiving mifepristone than in the control groups.

In the data analysis presented in this Example, hypokalemia was definedas a potassium value ≤3.4 mEq/L. When hypokalemia was reported as anadverse event (AE), the MedDRA dictionary coded the event as “decreasedblood potassium.” Seventeen subjects had reported treatment emergentadverse events (TEAEs) of decreased blood potassium. Three had reportedTEAEs of hypokalemia but did not have corresponding laboratory values oflow potassium recorded by the central laboratory.

Hypokalemia in the range of 2.4 to 3.4 mEq/L was seen in 61 of 782(7.8%) mifepristone treated subjects and 19 of 584 (3.3%) placebosubjects in previously performed double blind psychotic major depression(PMD) trials. Hypokalemia in the range of 2.8 to 3.5 mEq/L was seen in 9out of 33 subjects in an Alzheimer's study who had received 300 mg perday of mifepristone for 16 weeks. Out of 32 subjects in the placebo arm,none had a reported potassium level of 3.5 or lower. Clinicallymeaningful hypokalemia (≤3.1) has been reported in 16 of 821 (1.9%)mifepristone treated subjects (12 in completed double blind PMD trials,and 4 in a completed Alzheimer's trial), and in 5 of 626 (0.8%) placebotreated subjects in completed PMD trials.

The Cushing's syndrome study reported herein was conducted in accordancewith the Declaration of Helsinki and Good Clinical Practice (GCP)according to International Conference on Harmonization (ICH) guidelines.Patients enrolled in the clinical study were men or non-pregnant womenwho are at least 18 years of age who required medical treatment forendogenous Cushing's syndrome due to ectopic ACTH syndrome, adrenaltumors, adrenal hyperplasia, and Cushing's disease, who were notcandidates for pituitary surgery or who had failed or recurred afterpituitary surgery or were otherwise not candidates for pituitarysurgery.

Dosing Schedule Dosing was started with 300 mg of mifepristone once perday for 14 days. After 14 days, if no clinical improvement was seen butthe drug was well tolerated, the dose of mifepristone was increased to600 mg once per day. After 4 weeks of dosing at 600 mg once per day, ifno clinical improvement was seen but the drug was well tolerated, thedose was increased to 900 mg once per day. Dose escalation was based onweight with the maximum dose no higher than 20 mg/kg/day. Subjectsweighing <60 kg did not have the dose escalated beyond 900 mg once perday. After 4 weeks of dosing at 900 mg once per day, if no clinicalimprovement was seen but the drug was well tolerated, the dose wasincreased to 1200 mg once per day. Study duration was 24 weeks.

Serum electrolytes, including potassium, were measured regularlythroughout the study period. A patient was considered to havehypokalemia if the patient's potassium level fell below 3.5 mEq/L.Decreased potassium was observed during at least one visit in 17 of 34patients during the study (about 30%), some of these patients hadhypokalemia (potassium levels below 3.5 mEq/L) or edema.

47 subjects were part of either Etiology Group 1 (N=43, CushingSyndrome) or Etiology Group 2 (N=4, Ectopic). In these 47 subjects,There were 21 subjects total who had a Potassium value ≤3.5 mmol/L, atany of the six visits listed below. Therefore, 8 of the 21 (38%) had aPotassium value ≤3.5 mmol/L as early as day 14. They are: 007-010,008-014, 010-002, 011-003, 011-004, 015-005, 018-001, 024-001.

Further, there were 23 subjects total who had a Potassium value ≤3.5mmol/L, at any post-baseline visit. Of these 23 subjects, there werethree subjects with a day 7, Potassium value ≤3.5 mmol/L. They are015-002 and 020-002, 022-001, and 8 different subjects with a day 14Potassium value ≤3.5 mmol/L Thus, there were a total of 11 (48%) of 23subjects with a Potassium value ≤3.5 mmol/L as early as day 14, takingall post-baseline values into consideration.

Hypokalemia was generally mild to moderate and was often associated withalkalosis (elevated CO2) and variably associated with edema. Thehypokalemia responded to treatment with potassium supplementation;mineralocorticoid antagonists were also used. The doses of potassiumsupplements for these subjects ranged from 10 mEq daily to 340 mEq dailyand doses of spironolactone ranged from 50 mg to 300 mg daily. Foursubjects had potassium values that met the definition of severehypokalemia (≤2.5 mEq/L). In three of the four instances, there wereprevious potassium values that were low, although not in the severehypokalemic range, and these subjects were receiving treatment withpotassium; two were taking spironolactone. The potassium level increasedafter the episode of severe hypokalemia. Severe hypokalemia in onesubject occurred at the follow-up visit when the subject had not beentaking mifepristone for 6 weeks.

Summary of Subjects with Hypokalemia (Potassium ≤3.4 mEq/L) and SevereHypokalemia (Potassium <2.5 mEq/L)

A summary of subjects with hypokalemia (serum potassium ≤3.4 mEq/L [≤3.4mmol/L]) and severe hypokalemia (serum potassium ≤2.5 mEq/L [≤2.5mmol/L]) is presented in Table 7. Subjects were included in this tablebased on serum potassium values from laboratory testing, regardless ofwhether they had a reported adverse event (AE) with a preferred term of“decreased blood potassium” (three subjects had treatment emergentadverse events (TEAEs) of hypokalemia without corresponding lowpotassium values).

TABLE 7 Summary of Subjects with Hypokalemia and Severe HypokalemiaHypokalemia: Potassium ≤ 3.4 mEq/L); Severe Hypokalemia: Potassium ≤ 2.5mEq/L Treatment day or week of Number with Number with Severe [K]Hypokalemia (%) Hypokalemia (%) measurement (Potassium ≤ 3.4 mEq/L)(Potassium ≤ 2.5 mEq/L) Screen (prior to  5 (10%) treatment) Day 1 2(4%) Day 7 2 (4%) Day 14  8 (16%) 1 (2%) Day 28 10 (20%) Week 6  7 (14%)Week 8 4 (8%) Week 10 4 (8%) Week 12 3 (6%) 1 (2%) Week 16  5 (10%) 1(2%) Week 20 1 (2%) Week 24/Early 4 (8%) Termination 6 Week 3 (6%) 1(2%) Follow-Up Note: Subjects having Severe Hypokalemia are alsoincluded with subjects having Hypokalemia Overall Number of Subjects N =50

Hypokalemia was generally mild to moderate and was often associated withalkalosis (elevated CO2) and variably associated with edema. Thehypokalemia responded to treatment with potassium supplementation;mineralocorticoid antagonists were also used. The doses of potassiumsupplements for these subjects ranged from 10 mEq daily to 340 mEq dailyand doses of spironolactone ranged from 50 mg to 300 mg daily. Foursubjects had potassium values that met the definition of severehypokalemia (≤2.5 mEq/L): Subject 06-003 (at 6-week follow-up), Subject07-010 (at Week 16), Subject 15-005 (at Day 14), and Subject 18-001 (atWeek 12). In three of the four instances (not for Subject 15-005), therewere previous potassium values that were low, although not in the severehypokalemic range, and these subjects were receiving treatment withpotassium; two were taking spironolactone (Subjects 07-010 and 18-001).The potassium level increased after the episode of severe hypokalemia.The severe hypokalemia for Subject 06-003 occurred at the follow-upvisit when the subject had not been taking mifepristone for 6 weeks.

Hypokalemia can be related to elevations in cortisol that occur whenACTH rises as a result of glucocorticoid blockade produced bymifepristone. As cortisol levels rise, the normal mechanism toinactivate cortisol in the kidney is saturated (11-hydroxysteroiddehydrogenase type 2) and the mineralocorticoid receptor is activated.This state of apparent mineralocorticoid excess leads to hypokalemia(presumably from accentuated kaliuresis) as well as alkalosis, andedema. In this study, most cases of hypokalemia occurred early in thecourse of treatment. Hypokalemia responded to medical therapy, whichoften consisted of large amounts of supplemental potassium andmineralocorticoid antagonists. The episodes of severe hypokalemia werepreceded by declining potassium levels, indicating that aggressive earlyintervention might prevent severe episodes.

The levels of ACTH and cortisol increased in most subjects duringmifepristone treatment. Subjects with Cushing's disease could haveincreased ACTH production due to loss of a negative feedback loop withglucocorticoid receptor blockade. Patients who have had pituitarysurgery to treat Cushing's disease and who later undergo adrenalectomybecause of persistent hypercortisolism have a risk of increasedpituitary tumor volume when cortisol levels drop after adrenal surgery.Although the mechanism for increased pituitary volume afteradrenalectomy is not completely understood, increased tumor volume mayoccur due to the absence of negative feedback on the tumoralcorticotrophs; ACTH rises due to lack of negative feedback on itsproduction by cortisol. Theoretically, the same problem could arise withmifepristone treatment because glucocorticoid blockade stops thenegative feedback that controls ACTH levels. In the 43 subjects withCushing's disease, ACTH increased about two-fold and serum cortisolincreased to a smaller degree during mifepristone treatment.

Adverse events such as hypokalemia associated in some patients withmifepristone treatment can be, and for these patients was, managed,e.g., by potassium supplementation, administration of spironolactone, orother measures.

FIG. 1 shows the serum ACTH level of Cushing's syndrome patientsreceiving mifepristone treatment. The upper curve presents the serumACTH level of those Cushing's syndrome patients who experiencedhypokalemia during the course of treatment (patients also receivedtherapy for the hypokalemia as needed). The lower curve presents theserum ACTH level of those Cushing's syndrome patients who did notexperience hypokalemia during the course of treatment. Note that the twocurves are clearly separate at the second time point (14 days) whenpatients, who had been receiving 300 mg mifepristone per day from day 0to day 13, began receiving 600 mg mifepristone at day 14 and after.Thus, those patients who experienced hypokalemia can be identified veryearly on during treatment, and therapy for hypokalemia administered,even in the absence of low potassium at that time.

As shown in FIG. 1, Cushing's syndrome patients who experiencedhypokalemia during the course of their mifepristone treatment were thosepatients whose ACTH levels rose above about 100 pg/mL (e.g., above about112 pg/mL). Cushing's syndrome patients who experienced hypokalemiaduring the course of their mifepristone treatment exhibited ACTH levelsabove about 150 pg/mL, and above about 200 pg/mL, and above about 250pg/mL. In contrast, those Cushing's syndrome patients whose ACTH levelsdid not rise above about 100 pg/mL (e.g., remained below about 112pg/mL, and remained below about 150 pg/mL) did not experiencehypokalemia during the course of their mifepristone treatment.

These results allow the identification of Cushing's syndrome patients atrisk for developing hypokalemia during mifepristone treatment forCushing's syndrome. These results allow the differentiation betweenthose Cushing's syndrome patients at risk for developing hypokalemiaduring mifepristone treatment for Cushing's syndrome and those Cushing'ssyndrome patients at lower, or at no, risk for developing hypokalemiaduring mifepristone treatment for Cushing's syndrome. Suchidentification and differentiation allows for providing preventivetherapy for hypokalemia to those patients at most risk for hypokalemia,in advance of low potassium and so in advance of deleterious andpotentially life-threatening symptoms. In addition, such identificationand differentiation allows treating physicians to avoid providingunneeded hypokalemia therapy to those patients at least risk, or at norisk, for hypokalemia, thus avoiding any potential side-effects fromsuch treatment.

Example 3 Increased ACTH Levels Following Mifepristone Dose IncreasePredict Hypokalemia

Further inspection of FIG. 1 shows that the serum ACTH level ofCushing's syndrome patients showed different types of responses toincreases in mifepristone dosage. The upper curve (showing the serumACTH level of those Cushing's syndrome patients who experiencedhypokalemia) is not only higher, but also more irregularly shaped: thisindicates that these patients reacted more sharply to increases inmifepristone dose (even at later time periods than at the early, day 14measurements) than did patients who did not experience hypokalemiaduring the course of treatment.

Extensive modeling of low potassium levels among the N=47 subjects wasperformed to determine the best predictors of low potassium after startof mifepristone. The modeling was based on logistic regressions wherethe endpoint was categorical Low vs High Potassium levels(Non-Hypokalemic Potassium >3.5 mmol/L vs Hypokalemic Potassium ≤3.5mmol/L).

Potassium levels were obtained on every subject at either screening orthe pre-drug administration baseline visit, and then also at everyscheduled post-baseline visit. Potassium levels post-baseline weretherefore obtained as early as day 7 and through day 210 (week 30 wasthe last visit and was the 6 week follow-up visit). ACTH, and cortisolwere measured at six visits (week 2 (day 14), week 6 (day 42), week 10(day 70), week 16 (day 112), and week 24 (day 168) week 6 follow-up (day210)).

The logistic regression modeling was performed based on baseline ACTH,day 14 ACTH levels, and change at day 14 from baseline for ACTH. Themodeling was performed to find the best statistically significantpredictor with a sufficiently high sensitivity and specificity topredict which patients might be at risk for developing low potassiumlevels.

A stepwise logistic regression model predicting potassium levels ≤3.5mmol/L at any post-week 2 visit, based on only baselines and week 2variables (ACTH, cortisol, cortisol/ACTH ratio and potassium) showedthat ACTH at day 14 (SAS derived variable name ACTH14) was astatistically significant predictor of low potassium levels (P=0.0005,c-statistic=0.687).

A simple logistic regression analysis was further performed using onlyACTH on day 14 as the single independent predictor of low potassiumlevels at any post-week 2 visit. ACTH on day 14 was highly statisticallysignificant (P<0.0001, c-statistic=0.673). In addition, we produced theROC table showing for each value of ACTH14, the sensitivity andspecificity. The estimated threshold was determined where sensitivityand specificity are approximately equal at 108 mmol/L. Thus, ACTHgreater than about 100 pg/mL was a good predictor of later hypokalemia.

Further analyses confirm the usefulness of ACTH levels in predictinghypokalemia in Cushing's syndrome patients later on during therapy.Cross classification results by binary category of potassium level atthe respective visit and the ACTH category at Day 14 were examined. OnDay 28, of the 9 subjects with a low potassium, the logistic regressionmodel based only on the ACTH at day 14, predicts 7 of the 9 (77.8%)subjects with a low potassium level (Chi-squared P=0.007). Day 28, isthe best cross classification result. There were other fairly successfulpredictions on designated visits. On day 42, ACTH on day 14, predicts 4of the 6 (66.7%) subjects with a low potassium level (Chi-squaredP=0.069). On day 42, ACTH on day 14, predicts 4 of the 6 (66.7%)subjects with a low potassium level (Chi-squared P=0.069). On day 168(week 24), ACTH on day 14, predicts 4 of 5 (80%) of the subjects with alow potassium level (Chi-squared P=0.045).

As shown in FIG. 1, Cushing's syndrome patients who experiencedhypokalemia during the course of their mifepristone treatment were thosepatients whose ACTH levels rose by about 50 pg/mL to 100 pg/mL followingan initial increase in mifepristone dose. In contrast, those Cushing'ssyndrome patients who did not experience hypokalemia were those whoseACTH levels rose by only about 25 pg/mL following an initial increase inmifepristone dose. The FIGURE further shows that ACTH levels ofCushing's patients who experienced hypokalemia also rose (by about 75pg/mL to about 100 pg/mL) following subsequent increases in mifepristonedose (see, e.g., day 70, and day 168). In contrast, no such dramaticrises in ACTH levels following mifepristone dose increases were seen inCushing's patients who did not experience hypokalemia rose.

Thus, those patients who experienced hypokalemia can be identified notonly by the levels of ACTH measured in their blood, but also by the morepronounced changes (increases) in ACTH levels following mifepristonedose increases. This second identifying characteristic, which appearsvery early on during treatment, and also at later times duringtreatment, allows for preventive therapy for hypokalemia to beadministered when the signal is recognized, even in the absence of lowpotassium at that time.

Example 4

ACTH Visit Change Values from Baseline Predict Hypokalemia

Comparison of ACTH visit change values from baseline shows significantdifferences between non-hypokalemic Cushing's syndrome patients andthose Cushing's syndrome patients who experienced hypokalemia during thestudy period. The difference in change values seen betweennon-hypokalemic and hypokalemic patients by treatment day 70 allowsprophylactic treatment relatively early on during treatment, in order toprevent the development of, or worsening of, and to allow reversal of,hypokalemia in those patients identifiable by the high ACTH visit changevalues at day 70 (e.g., patients with ACTH visit change values of about200 ng/L or above). Patients were from both Etiology Group 1 (pituitaryCushing's disease) and from Etiology Group 2 (ectopic Cushing's) (N=47).

TABLE 8 ACTH (ng/L) Visit Change Values from Baseline Non- t-test Mean ±SD (N) Hypokalemic Hypokalemic P-Value Day 14 30.6 ± 26.9 (38)  60.8 ±99.6 (8) 0.1 Day 42 40.6 ± 54.7 (35)  86.3 ± 58.2 (6) 0.07 Day 70 49.2 ±22.5 (30) 211.8 ± 147.5 (6) 0.0002 Day112 70.2 ± 82.2 (23) 101.4 ± 159.6(9) 0.5 Day 168 48.2 ± 73.8 (37) 151.2 ± 166.5 (5) 0.02 Day 210 13.4 ±34.0 (37) 113.7 ± 167.7 (3) 0.002

Thus, those patients who experienced hypokalemia can be identified bycomparison of the ACTH change values with the ACTH baseline value. Thisfurther identifying characteristic further allows for preventive therapyfor hypokalemia to be administered when the signal is recognized, evenin the absence of low potassium at that time.

Example 5

ACTH Visit Change Values from Baseline Predict Hypokalemia

Comparison of the ratio of ACTH visit change values from baselinedivided by baseline ACTH value shows significant differences betweennon-hypokalemic Cushing's syndrome patients and those Cushing's syndromepatients who experienced hypokalemia during the study period. Thus, atvisit day 70, those patients who experienced hypokalemia can beidentified by comparison of the ratio of ACTH visit change values frombaseline divided by the ACTH baseline value. This further identifyingcharacteristic further allows for preventive therapy for hypokalemia tobe administered when the signal is recognized, even in the absence oflow potassium at that time.

TABLE 9 Ratio of ACTH Visit Change Values from Baseline per BaselineEtiology Groups 1 and 2 (N = 47) Mean ± SD (N) ACTH_CHG/ Non- t-testACTH Baseline Hypokalemic Hypokalemic P-Value Day 14 1.77 ± 0.72 (38)1.87 ± 1.32 (8) 0.8 Day 42 2.02 ± 0.97 (35) 2.50 ± 0.61 (6) 0.3 Day 702.06 ± 1.01 (30) 4.08 ± 2.51 (6) 0.002 Day112 2.47 ± 1.87 (23) 2.53 ±1.49 (9) 0.9 Day 168 2.08 ± 1.31 (37) 3.30 ± 2.54 (5) 0.09 Day 210 1.33± 0.61 (37) 1.36 ± 0.46 (3) 0.9

Similar differentiation between Cushing's patients who experiencedhypokalemia during mifepristone treatment, and those who did not, wasalso obtained by calculating the ratio of ACTH level at a particularvisit day divided by ACTH baseline level (i.e., essentially the sameP-value results are seen if the ratio is defined as ACTH/ACTH baseline).

Example 6 Total Serum Cortisol Visit Values Predict Hypokalemia

Comparison of Total Serum cortisol (nmol/L) visit values showssignificant differences between non-hypokalemic Cushing's syndromepatients and those Cushing's syndrome patients who experiencedhypokalemia during the mifepristone treatment study period.

TABLE 10 Total Serum Cortisol (nmol/L) Visit Values Non- t-test Mean ±SD (N) Hypokalemic Hypokalemic P-Value Day 14 782 ± 246 (38) 1261 ± 786(8) 0.002 Day 42 828 ± 249 (35) 1274 ± 401 (6) 0.0007 Day 70 1025 ± 546(30)  1390 ± 283 (6) 0.1 Day112 813 ± 318 (23) 1318 ± 677 (9) 0.007 Day168 948 ± 537 (37) 1298 ± 597 (5) 0.2 Day 210 696 ± 477 (37) 1228 ± 561(3) 0.07

As shown in Table 10, Cushing's syndrome patients who experiencedhypokalemia during the course of their mifepristone treatment were thosepatients whose total serum cortisol levels were above about 1000 nmol/L(e.g., above about 1100 nmol/L, or about 1200 nmol/L) early on duringmifepristone treatment (e.g., day 14 and day 42). In contrast, Cushing'ssyndrome patients who did not experience hypokalemia had total serumcortisol levels below about 1000 nmol/L (e.g., below about 900 nmol/L,or below about 800 nmol/L) early on during mifepristone treatment (e.g.,at day 14 and/or day 42). Such differences also persisted throughout thetreatment period, with hypokalemia patients having total serum cortisollevels above about 1000 nmol/L (e.g., above about 1100 nmol/L, or about1200 nmol/L) throughout the treatment period, and even above about 1300nmol/L on day 112. In contrast, Cushing's syndrome patients who did notexperience hypokalemia had total serum cortisol levels below about 1000nmol/L on every measurement day except day 70; and had total serumcortisol levels below about 900 nmol/L on all other days throughout themifepristone treatment period.

Thus, Cushing's patients who experienced hypokalemia were those whosetotal serum cortisol was high at early time during treatment, allowingearly identification and differentiation of those Cushing's patients atrisk for developing hypokalemia, and allowing early intervention withhypokalemia therapy in order to avoid, or reduce the severity of, andeventually to reverse, hypokalemia in Cushing's syndrome patientsreceiving mifepristone treatment.

Thus, measurement of total serum cortisol can also be used to determinethe risk for, and to identify those patients at risk for, hypokalemia,and by providing early hypokalemia therapy, may prevent or amelioratehypokalemia in Cushing's syndrome patients receiving mifepristonetherapy. This yet further identifying characteristic, which appears veryearly on during treatment, and also at later times during treatment,allows for preventive therapy for hypokalemia to be administered whenthe signal is recognized, even in the absence of low potassium at thattime.

Example 7 24-Hour Urine Cortisol Visit Values Predict Hypokalemia

Comparison of 24-hour Urine cortisol (nmol/24 hour) visit values showssignificant differences between non-hypokalemic Cushing's syndromepatients and those Cushing's syndrome patients who experiencedhypokalemia during the study period.

TABLE 11 24 Hour Urine Cortisol (nmol/24 hr) Visit Values EtiologyGroups 1 and 2 (N = 47) Non- t-test Mean ± SD (N) HypokalemicHypokalemic P-Value Day 42  886 ± 1060 (35) 4373 ± 5347 (6) 0.0007 Day70 1696 ± 3387 (30) 9132 ± 9321 (6) 0.002 Day 112 1314 ± 3351 (23) 3552± 2827 (9) 0.09 Day 168 1444 ± 3127 (36) 5615 ± 5053 (5) 0.01 Day 2101423 ± 6086 (35) 5129 ± 6335 (3) 0.3

As shown in Table 11, Cushing's syndrome patients who experiencedhypokalemia during the course of their mifepristone treatment were thosepatients whose 24-hour urine cortisol levels were above about 2000nmol/24 hr (e.g., above about 2500 nmol/24 hr, or above about 3000nmol/24 hr, or above about 4000 nmol/24 hr, or above about 5000 nmol/24hr, or above about 6000 nmol/24 hr, or above about 7000 nmol/24 hr, orabove about 8000 nmol/24 hr, or above about 9000 nmol/24 hr, all ofwhich 24 hour urine cortisol levels are above those found for Cushing'ssyndrome patients who did not experience hypokalemia). The 24 hour urinecortisol measurements are different between the two groups of patientsfairly early during mifepristone treatment (e.g., day 42 and day 70) andallow early identification of patients at risk. (No 24 hour urinecortisol measurement was obtained on day 7 of the study.) In contrast tothe Cushing's patients who experienced hypokalemia, Cushing's syndromepatients who did not experience hypokalemia had 24 hour urine cortisollevels below about 1700 nmol/24 hr (e.g., below about 1000 nmol/24 hr)at all times during mifepristone treatment.

Thus, Cushing's patients who experienced hypokalemia were those whose 24hour urine cortisol levels were high at early, and at all, times duringtreatment, allowing early identification and differentiation of thoseCushing's patients at risk for developing hypokalemia, and allowingearly intervention with hypokalemia therapy in order to avoid, or reducethe severity of, and eventually to reverse, hypokalemia in Cushing'ssyndrome patients receiving mifepristone treatment. Thus, measurement of24 hour urine cortisol levels can also be used to determine the riskfor, and to identify those patients at risk for, hypokalemia, and byproviding early hypokalemia therapy, may prevent or amelioratehypokalemia in Cushing's syndrome patients receiving mifepristonetherapy. This yet further identifying characteristic, which appears veryearly on during treatment, and also at later times during treatment,allows for preventive therapy for hypokalemia to be administered whenthe signal is recognized, even in the absence of low potassium at thattime.

Thus, in embodiments, Applicant discloses methods for treating an adultpatient with endogenous Cushing's syndrome having type 2 diabetesmellitus or glucose intolerance to control hyperglycemia secondary tohypercortisolism and for reducing the risk of/preventing the developmentof hypokalemia in the patient, the methods comprising: a) administeringto the patient an effective amount of a therapeutic agent for treatinghypokalemia, wherein the patient is one whose 24-hour urine cortisollevels were above about 2000 nmol/24 hr (e.g., above about 2500 nmol/24hr, or above about 3000 nmol/24 hr, or above about 4000 nmol/24 hr, orabove about 5000 nmol/24 hr, or above about 6000 nmol/24 hr, or aboveabout 7000 nmol/24 hr, or above about 8000 nmol/24 hr, or above about9000 nmol/24 hr, and wherein the patient does not have a lower thannormal potassium level; whereby the patient is treated to controlhyperglycemia secondary to hypercortisolism and the risk of developinghypokalemia is reduced or hypokalemia is prevented in the patient. Thetherapeutic agent for treating hypokalemia may be, e.g., amineralocorticoid receptor antagonist (e.g., spironolactone) or apotassium supplement. In embodiments, step (a) comprises administeringto the patient the therapeutic agent for hypokalemia just before, or atabout the same time as, administering to the patient a second and higherdose of GRM. In embodiments, the first dose of GRM has been administeredto the patient prior to step (a), e.g., for at least two weeks. Inembodiments, the GRM is mifepristone; wherein the first dose ofmifepristone is 300 mg/day, 600 mg/day, or 900 mg/day of mifepristone.In embodiments, the patient has failed surgery, or is not a candidatefor surgery, for Cushing's syndrome. In embodiments, the methods furtherinclude, prior to step (a), the steps of: (i) administering to thepatient at least once the first dose of GRM; and (ii) obtaining a bloodsample from the patient to determine the patient's morning serum ACTHlevel. cortisol level.

Example 8

24-Hour Urine Cortisol Visit Change Values from Baseline PredictHypokalemia

Comparison of 24-hour Urine cortisol (nmol/24 hour) visit change valuesfrom baseline shows significant differences non-hypokalemic Cushing'ssyndrome patients and those Cushing's syndrome patients who experiencedhypokalemia during the study period.

TABLE 12 24 Hour Urine Cortisol (nmol/24 hr) Visit Change Values fromBaseline Etiology Groups 1 and 2 (N = 47) Non- t-test Mean ± SD (N)Hypokalemic Hypokalemic P-Value Day 42  329 ± 967 (35)  641 ± 3678 (6)0.7 Day 70 1045 ± 3500 (30)  4856 ± 4805 (6) 0.04 Day112 104 ± 5293 (23)2916 ± 2593 (9) 0.1 Day 168 512 ± 4575 (36) 4128 ± 6624 (5) 0.1 Day 210471 ± 2843 (35) 2497 ± 3776 (3) 0.3

As shown in Table 12, Cushing's syndrome patients who experiencedhypokalemia during the course of their mifepristone treatment were thosepatients whose change in 24-hour urine cortisol levels (as compared totheir baseline 24-hour urine cortisol levels) was greater than about 600nmol/24 hr on day 42, and higher (e.g., greater than about 4000 or about5000 nmol/24 hr on day 70). Such change in 24-hour urine cortisol levels(as compared to their baseline 24-hour urine cortisol levels) wasgreater than that observed for Cushing's syndrome patients who did notexperience hypokalemia during the course of their mifepristonetreatment.

Thus, change in 24-hour urine cortisol levels (as compared to theirbaseline 24-hour urine cortisol levels) is another differentiatingfactor that may be used to identify Cushing's syndrome patients at riskfor hypokalemia. This differentiating factor may also be used toidentify and differentiate between the two groups of patients, and toallow early identification of patients at risk. Such identification ofthose Cushing's patients at risk for developing hypokalemia allows theearly intervention with hypokalemia therapy in order to avoid, or reducethe severity of, and eventually to reverse, hypokalemia in Cushing'ssyndrome patients receiving mifepristone treatment.

Thus, in embodiments, Applicant discloses methods for treating an adultpatient with endogenous Cushing's syndrome having type 2 diabetesmellitus or glucose intolerance to control hyperglycemia secondary tohypercortisolism and for reducing the risk of/preventing the developmentof hypokalemia in the patient, the methods comprising: a) administeringto the patient an effective amount of a therapeutic agent for treatinghypokalemia, wherein the patient prior to step (a) has been administeredat least once a first dose of glucocorticoid receptor modulator (GRM)and the change in the patient's 24-hour urinary cortisol levels ascompared to their baseline 24-hour urinary cortisol levels) was greaterthan about 600 nmol/24 hr on day 42, and higher (e.g., greater thanabout 4000 or about 5000 nmol/24 hr on day 70), and wherein the patientdoes not have a lower than normal potassium level; whereby the patientis treated to control hyperglycemia secondary to hypercortisolism andthe risk of developing hypokalemia is reduced or hypokalemia isprevented in the patient. The therapeutic agent for treating hypokalemiamay be, e.g., a mineralocorticoid receptor antagonist (e.g.,spironolactone) or a potassium supplement. In embodiments, step (a)comprises administering to the patient the therapeutic agent forhypokalemia just before, or at about the same time as, administering tothe patient a second and higher dose of GRM. In embodiments, the firstdose of GRM has been administered to the patient prior to step (a),e.g., for at least two weeks. In embodiments, the GRM is mifepristone;wherein the first dose of mifepristone is 300 mg/day, 600 mg/day, or 900mg/day of mifepristone. In embodiments, the patient has failed surgery,or is not a candidate for surgery, for Cushing's syndrome. Inembodiments, the methods further include, prior to step (a), the stepsof: (i) administering to the patient at least once the first dose ofGRM; and (ii) obtaining a blood sample from the patient to determine thepatient's morning serum ACTH level. cortisol level.

Example 9 24-Hour Urine Cortisol Divided by ACTH Predicts Hypokalemia

Comparison of the ratios of 24-hour Urine cortisol (nmol/24 hour)divided by ACTH visit values from baseline shows significant differencesnon-hypokalemic Cushing's syndrome patients and those Cushing's syndromepatients who experienced hypokalemia during the study period.

TABLE 13 24 Hour Urine Cortisol (nmol/24 hr)/ACTH Ratio Visit ValuesEtiology Groups 1 and 2 (N = 47) Non- t-test Mean ± SD (N) HypokalemicHypokalemic P-Value Day 42  7.9 ± 6.0 (35) 26.1 ± 18.4 (6) 0.0001 Day 7017.0 ± 32.7 (30) 33.5 ± 16.1 (6) 0.3 Day112  9.6 ± 16.3 (23) 30.9 ± 31.0(9) 0.02 Day 168 12.4 ± 15.5 (36)  19.3 ± 9.5 (5) 0.3 Day 210 12.5 ±27.9 (35)  11.5 ± 7.5 (3) 0.9

As shown in Table 13, the ratio of 24-hour urine cortisol value dividedby the ACTH level measured at the same visit day can be used todifferentiate between Cushing's syndrome patients who experiencedhypokalemia during the course of their mifepristone treatment andCushing's syndrome patients who did not experience hypokalemia duringthe course of their mifepristone treatment. Cushing's syndrome patientsexperiencing hypokalemia had ratios of 24-hour urine cortisol valuesdivided by ACTH values greater than about 20 (e.g., greater than about25, or greater than about 30, or greater than about 35). In contrast,Cushing's syndrome patients who did not experience hypokalemia hadratios of 24-hour urine cortisol values divided by ACTH values less thanabout 20 (e.g., less than about 15 on most days, and less than about 10on days 42 and 112).

Thus, the ratio of 24-hour urine cortisol values divided by ACTH valuesis another differentiating factor that may be used to identify Cushing'ssyndrome patients at risk for hypokalemia. This differentiating factormay also be used to identify and differentiate between the two groups ofpatients, and to allow early identification of patients at risk. Suchidentification of those Cushing's patients at risk for developinghypokalemia allows the early intervention with hypokalemia therapy inorder to avoid, or reduce the severity of, and eventually to reverse,hypokalemia in Cushing's syndrome patients receiving mifepristonetreatment.

Thus, in embodiments, Applicant discloses methods for treating an adultpatient with endogenous Cushing's syndrome having type 2 diabetesmellitus or glucose intolerance to control hyperglycemia secondary tohypercortisolism and for reducing the risk of/preventing the developmentof hypokalemia in the patient, the methods comprising: a) administeringto the patient an effective amount of a therapeutic agent for treatinghypokalemia, wherein the patient prior to step (a) has been administeredat least once a first dose of glucocorticoid receptor modulator (GRM)and the ratio of the patient's 24-hour urinary cortisol divided by thepatient's serum ACTH level is at least about 20, and wherein the patientdoes not have a lower than normal potassium level; whereby the patientis treated to control hyperglycemia secondary to hypercortisolism andthe risk of developing hypokalemia is reduced or hypokalemia isprevented in the patient. The therapeutic agent for treating hypokalemiamay be, e.g., a mineralocorticoid receptor antagonist (e.g.,spironolactone) or a potassium supplement. In embodiments, step (a)comprises administering to the patient the therapeutic agent forhypokalemia just before, or at about the same time as, administering tothe patient a second and higher dose of GRM. In embodiments, the firstdose of GRM has been administered to the patient prior to step (a),e.g., for at least two weeks. In embodiments, the GRM is mifepristone;wherein the first dose of mifepristone is 300 mg/day, 600 mg/day, or 900mg/day of mifepristone. In embodiments, the patient has failed surgery,or is not a candidate for surgery, for Cushing's syndrome. Inembodiments, the methods further include, prior to step (a), the stepsof: (i) administering to the patient at least once the first dose ofGRM; and (ii) obtaining a blood sample from the patient to determine thepatient's morning serum ACTH level. cortisol level.

Example 10

Numbers of Subjects with Potassium Values Less than or Equal to 3.5mEq/L

There were 21 subjects total who had a Potassium values<=3.5 mmol/L, atany of the six visits listed below. Therefore, 8 of the 21 (38%) had aPotassium value<=3.5 mmol/L as early as day 14. They are: 007-010,008-014, 010-002, 011-003, 011-004, 015-005, 018-001, 024-001. Further,there were 23 subjects total who had a Potassium values<=3.5 mmol/L, atany post-baseline visit. Of these 23 subjects, there were three subjectswith a day 7, Potassium value<=3.5 mmol/L. They are 015-002 and 020-002,022-001, and 8 different subjects with a day 14 Potassium value<=3.5mmol/L

Thus, there were a total of 11 (48%) of 23 subjects with a Potassiumvalue<=3.5 mmol/L as early as day 14, taking all post-baseline valuesinto consideration. There were 4 subjects total (all in Etiologygroup 1) who had Potassium values<=2.5 mmol/L; Subject 006-003 had apotassium value of 2.5 at the 6 week follow up (day 210), Subject007-010 had a potassium value of 2.1 at the week 16 (day 112), Subject015-005 had a potassium value of 2.5 at the Day 14, Subject 018-001 hada potassium value of 2.2 at the week 12 (day 84, not shown in tablebelow), (Etiology Groups 1 and 2 (N=47)

TABLE 14 Number of Subjects with Potassium values <= 3.5 mmol/L EtiologyGroups 1 and 2 (N = 47) Non- Hypokalemic Hypokalemic >3.5 mmol/L <=3.5mmol/L Day 14 38 8 Day 42 35 6 Day 70 30 6 Day112 23 9 Day 168 37 5 Day210 37 3

What is claimed is:
 1. A method of treating an adult endogenousCushing's syndrome patient to control hyperglycemia secondary tohypercortisolism while reducing the risk of developing hypokalemia orpreventing the development of hypokalemia in said patient, the patienthaving a normal level of potassium and suffering type 2 diabetesmellitus or glucose intolerance, the method comprising: (a)administering a glucocorticoid receptor modulator (GRM) to the patient;and (b) administering to the patient an effective amount of atherapeutic agent for treating hypokalemia, wherein the patient'smorning serum ACTH level is at least about 112 pg/mL afteradministration of said GRM, and wherein the patient does not have alower than normal potassium level when administered said therapeuticagent for treating hypokalemia, whereby the patient is treated tocontrol hyperglycemia secondary to hypercortisolism and the risk ofdeveloping hypokalemia is reduced or hypokalemia is prevented in thepatient.
 2. The method of claim 1, wherein the patient suffers fromACTH-dependent Cushing's syndrome.
 3. The method of claim 1, whereinstep (a) comprises administering to the patient said therapeutic agentfor hypokalemia just before or at about the same time of administeringto the patient a second and higher dose of GRM.
 4. The method of claim1, wherein step (a) comprises administering said GRM to the patientdaily for at least two weeks.
 5. The method of claim 1, wherein thetherapeutic agent for treating hypokalemia comprises a mineralocorticoidreceptor antagonist or a potassium supplement.
 6. The method of claim 5,wherein the mineralocorticoid receptor antagonist comprisesspironolactone.
 7. The method of claim 1, wherein the GRM comprisesmifepristone.
 8. The method of claim 7, wherein the first dose ofmifepristone is 300 mg/day, 600 mg/day, or 900 mg/day of mifepristone.9. The method of claim 1, wherein the patient has failed surgery, or isnot a candidate for surgery, for Cushing's syndrome.
 10. The method ofclaim 4, wherein the GRM comprises mifepristone.
 11. A method oftreating an adult patient with endogenous Cushing's syndrome to controlhyperglycemia secondary to hypercortisolism while reducing the risk ofdeveloping hypokalemia or preventing the development of hypokalemia insaid patient, the patient having a normal level of potassium andsuffering type 2 diabetes mellitus or glucose intolerance, the methodcomprising: (a) administering a glucocorticoid receptor modulator (GRM)to the patient; and (b) administering to the patient an effective amountof a therapeutic agent for treating hypokalemia, wherein the patient'smorning serum ACTH level is at least about 1.5 times the patient'sbaseline morning serum ACTH level after administration of said GRM,wherein said baseline morning serum ACTH level is determined prior toGRM administration, and wherein the patient does not have a lower thannormal potassium level when administered said therapeutic agent fortreating hypokalemia, whereby the patient is treated to controlhyperglycemia secondary to hypercortisolism and the risk of developinghypokalemia is reduced or hypokalemia is prevented in the patient. 12.The method of claim 11, wherein the patient suffers from ACTH-dependentCushing's syndrome.
 13. The method of claim 11, wherein step (a)comprises administering to the patient said therapeutic agent forhypokalemia just before or at about the same time of administering tothe patient a second and higher dose of GRM.
 14. The method of claim 11,wherein step (a) comprises administering said GRM to the patient dailyfor at least two weeks.
 15. The method of claim 11, wherein thetherapeutic agent for treating hypokalemia comprises a mineralocorticoidreceptor antagonist or a potassium supplement.
 16. The method of claim14, wherein the mineralocorticoid receptor antagonist is spironolactone.17. The method of claim 11, wherein the GRM comprises mifepristone. 18.The method of claim 17, wherein the first dose is 300 mg/day, 600mg/day, or 900 mg/day of mifepristone.
 19. The method of claim 11,wherein the patient has failed surgery, or is not a candidate forsurgery, for Cushing's syndrome.
 20. The method of claim 14, wherein theGRM comprises mifepristone.